The question of whether or not there's a word for "nerd" in Chinese has recently come up, in Mark Liberman's "'Your passport has just been stamped for entry into the Land of Bullshit'".
Mark quotes Tom Scocca, who cites three terms: fáwèi de rén 乏味的人 ("a dull and tasteless person"), diànnǎomí 电脑迷 ("someone excessively enthusiastic about computers"), and shūdāizi 书呆子 ("bookworm; pedant").
But none of these expressions comes close to functioning the way "nerd" does in contemporary American society. The first, fáwèi de rén, is a makeshift, ad hoc dictionary definition that explains a small part of what "nerd" signifies, but is not a set term that has the social-intellectual resonance and reach of "nerd". The second, diànnǎomí, is simply incorrect as even a translation of "nerd", since some people have called me a nerd, but I am absolutely terrified of computers (all of my good friends know that very well), though it might serve as a partial definition-explanation of "geek" (more about that below). The third, shūdāizi, is often invoked as a Chinese functional equivalent of "nerd", but even many of the people who mention it do so a bit sheepishly and admit that it's not really the same thing as "nerd", whereas most people (myself included) will say that it's not even remotely equivalent to "nerd".
I would like to discuss the problem of "nerd" in Chinese from a broader standpoint, namely, how ideas and concepts — and the words that signify them — pass from one culture to another.
So let's continue our examination of the question of how to say "nerd" in Chinese. First of all, we have to know what "nerd" itself means. It doesn't just signify a bookish or pedantic person, but rather someone who is socially inept or square (try finding an exactly equivalent word for that in Chinese!), perhaps, but not necessarily, because of a consuming commitment to intellectual or technical pursuits (in my case it's Language Log).
I asked about thirty native speakers of various Sinitic languages and topolects how they would say "nerd" in Chinese. Around half of them flat out said that you cannot say "nerd" in Chinese, but must borrow the English word. Roughly another quarter mentioned shūdāizi ("bookworm"), or variants thereof, while another quarter listed all sorts of colorful terms meaning — more or less — "fool; blockhead; dolt; dunce; dullard; simpleton; numskull"; etc.), none of which are really comparable to "nerd". I'll just list a few of the more interesting Chinese terms of the latter sort:
chǔnrén 蠢人 ("dolt") — note the two "worm / bug" radicals!)
dāizi 呆子 ("fool; sucker; idiot; goon; gawk; simpleton; calf; blockhead") — this is the shūdāizi 书呆子 ("bookworm") discussed above, but without the book at the beginning
shǎguā 傻瓜 ("muddle-headed melon") — this is one of my favorite words in Mandarin; can be used endearingly
chǔnhuò 蠢货 ("stupid goods")
Here follow some expressions from topolects whose pronunciations I'm not sure about, so I will usually give only the characters and the meanings, though I will make a stab in the dark for some of the pronunciations where I have a bit of a clue.
zaak6 naam4 宅男 ("home boy / man") — see the brief discussion of Japanese otaku and the derived Cantonese terms below
电车男 ("trolley / tram / streetcar boy / man")
隐蔽青年 ("secluded / hidden / sequestered youth") — mostly used in very formal situations, like news broadcasting and in printed media
薯仔 ("yam young'un") — "has multiple meanings, but is mostly used to describe a person who is dowdy, unhip, and a bit antediluvian"
愣子 ("person who is dazed / blank / dumb")
楞蛋 ("angular / square egg") — close to the "square" I talked about above
愣头青 ("blank-head youth")
憨包 ("foolish bag")
猪脑壳 ("pig skull")
哈儿 ("gaper" [?] — I honestly don't know the derivation of this term)
闷（达儿) ("imbecile" [?])
莽子 ("boor" [?])
Suzhouese and Shanghainese:
gangnin (don't know the tones) 戆[赣 above 心 below]人 ("muddlehead") — one of my informants comments:
There is a word that sounds like gǎngníng 港宁 [VHM: "port middle", but the characters are here being used strictly for the purpose of transcribing the Shanghainese sounds of the word in question], yet it does't exactly mean "nerd". It can be used affectionately towards children when they are acting silly, or towards somebody close who is "dorky". I think "dork" would be closer to the meaning? Either way, it's more of an affectionate name than an actual title. The more hostile version of 港宁, which is gǎngdù 港度 (it sounds like that, I'm not sure how to write the words) [VHM: neither my informant nor I know how to write this Shanghainese word in characters, nor how to transcribe it in Roman letters], which is "idiot". It can be used both affectionately and offensively.
N.B.: It is widely believe that this Shanghainese and Suzhouese term should be written as 憨人 ("simpleton") in characters, but the proper characters are as given above (see Wāng Píng 汪平, Xuéshuō Sūzhōu huà《学说苏州话》(Learning to Speak Suzhouese).
书毒头 ("egghead" [?]) — has a complimentary connotation
书蠹头 ("book worm-eaten/infested head")
This is obviously another way of writing the previous term, which — character by character — literally means "book poison head"! Clearly, there is no consensus among Wu speakers about how to write the second syllable. One informant put it this way: "…[It]'s impossible to write it. However, I'm guessing that the first character is 书 ["book"], and the last is 头 ["head"], but nobody in our family knew what the middle 'duh' is. It could be 读, or 独. Or maybe nothing at all, just a sound." Another informant told me it might be 倒.
I'm not sure how to transcribe the pronunciation of this word in either Suzhouese or Shanghainese, but it's something like siduhdeu.
"…people would say something that sounds like 'come-come'; it's not a literal term but very commonly used in daily conversation; can be derogatory or complimentary, depending upon the context"
All of these terms, and I could list many more, attest to the rich vocabulary for referring to fools and simpletons in Chinese, but none of them means what "nerd" does.
Here are some new usages in Mandarin that aren't really stabilized yet (in many cases, it is not evident how or why they have come to mean something like "nerd"):
Kǒng Zǐ 孔子 ("Confucius")
lǐkē nán 理科男 ("science male") — colloquial
èr 二 ("two") — a couple of my informants mentioned this as recently being used in contexts that resemble those in which "nerd" appears in English
zháinán/nǚ 宅男／女 ("home boy / girl") — these and related terms with zhái 宅 ("home; residence") in them must derive from Japanese otaku. For the origins of this usage in Japanese, Wikipedia puts it this way:
Otaku is derived from a Japanese term for another's house or family (お宅, otaku). This word is often used metaphorically, as an honorific second-person pronoun. In this usage, its literal translation is "you"…. The modern slang form, which is distinguished from the older usage by being written only in hiragana (おたく) or katakana (オタク or, less frequently, ヲタク), or rarely in rōmaji, appeared in public discourse in the 1980s, through the work of humorist and essayist Akio Nakamori. His 1983 series An Investigation of "Otaku" (『おたく』の研究 "Otaku" no Kenkyū?), printed in the lolicon [VHM: "Lolita Complex"] magazine Manga Burikko, applied the term to unpleasant fans in caricature.
The Japanese Wikipedia page on otaku reads:
中森が連載した『「おたく」の研究 』（1983年）の中で、アニメや漫画の愛好者が二人称として「御宅」という語を使う異質性から、その人間類型をおたくと呼称することが提案された。中森 はオタクを非常に否定的な文脈で記述しており、
But Japanese doesn't have one specific word for "nerd," as evidenced in part by the translation of Revenge of the Nerds as ナーズの復讐 (ふくしゅう), where the English word is transcribed in katakana (nāzu).
One of my correspondents tells me that her Korean friends say something like "pabao" to mean "nerd".
On the internet, we often encounter guàikā 怪咖 ("weirdo; freak") — this started in Taiwan among Taiwanese speakers but has now been picked up by Mandarin speakers as well. One of my correspondents suggested this as a possible Chinese equivalent for "nerd". I suspect, rather, that it is a fusion of the Chinese word for "strange / odd / queer" and the English word "geek", the second syllable serving as a transcription of the final consonant of the English word. And this brings up the problem of "nerd" versus "geek", another word whose meaning and nuances are very hard to express with a single Chinese word.
In this case, rather than relying on approximations like shūdāizi 书呆子 ("bookworm; pedant") or borrowing the English word directly, it seems that transcription is favored, e.g., jíkè 极客, qíkè奇客. There are many transcriptional forms for "geek(y)" in Hong Kong Cantonese, such as 騎呢, 怪鸡，搞机… too many to list.
In Japanese, for "geek", one might in some situations say -kon 控. See "Morpheme(s) of the Year".
In Cantonese, as in Japanese and other East Asian languages, "nerd" and "geek" seem to get blended together. Here are relevant entries from Bob Bauer's forthcoming ABC Cantonese-English Dictionary:
zaak6 naam4 宅男 (lit., "house male") term was likely originally borrowed from Japanese into Taiwan Mandarin in 2005 in connection with the broadcast of the popular Japanese TV drama "Densha otoko" 电车男 ("train man"); term is similar in meaning to duk6 naam4 毒男 (lit., "poisonous male") DEFINITION: nerd, geek: a young man who barricades himself in his room at home and spends most of the time surfing the internet on his computer, playing video games, avoiding face-to-face interaction and communication with other people, esp. women, and neglecting his physical appearance and personal hygiene
duk6 naam4 毒男 (lit., "poisonous male") term is similar in meaning to zaak6 naam4 宅男 (lit., "house male") young man who is single, introverted, socially-inept, unpopular with girls, and spends most of his time shut up in his room surfing the internet
We've often discussed the problem of "letter words" and English terms becoming a part of the Chinese lexicon and indeed of the alphabet becoming a part of the Chinese writing system, e.g., this post and the references therein.
A very common expression in China nowadays is "PK". It most likely comes from "player killer" in "Counter-Strike" and other popular video games in net cafe culture (though there are competing theories of its origins) and means "to thoroughly dominate" or "to beat" in competition. It may also be used in the sense of "call out" or "make a comparison between multiple contestants."
Several things to note about PK:
1. People who left China just a few years ago simply do not know this kind of very popular language.
2. PK is not an abbreviation or acronym of a Chinese term, but it now has become Chinese.
3. People who use terms such as PK freely must, whether directly or indirectly, consciously or unconsciously, be aware of their basis in English.
4. PK and such terms are part of global culture. They are neither merely English nor borrowed Chinese terms.
5. As so often happens when words cross from one language to another language, it does not mean exactly the same thing in Chinese ("to thoroughly dominate; to beat" [in one-on-one or multiple competition]) that it means in English ("player killer").
Brendan O'Kane and Matt Smith have done a considerable amount of research on this term (PK) in Chinese. If anyone has a particular interest in the origins and usage of "PK" in China, I could share their notes.
To sum up, even those informants who said that shūdāizi ("bookworm") is the closest you can get to "nerd" in Chinese recognize that it is very different from the latter word in English. Many young people, especially in Hong Kong and also in Taiwan, simply use the English word "nerd"; the English word is also increasingly used on the Mainland. A graduate student from the Mainland states: "I've never heard a translation for 'nerd'. If someone in China says it, the word must be in English." Another graduate student from the Mainland declares: "When we talk about a geek in Chinese, we only say 'geek', using the English word. No Chinese word can deliver the exact meaning."
Many Chinese speakers are aware of the subtle differences and similarities between "nerd" and "geek", as is evidenced by this article, which comes with a neat Venn diagram.
And here is an English article that distinguishes among "geek", "nerd", "dork" and "dweeb", which comes with an even neater Venn diagram.
To return to the main theme of this essay, "how ideas and concepts — and the words that signify them — pass from one culture to another", this is what borrowing is all about. When one culture in contact with another culture discovers an idea / term that it considers to be lacking in its own culture and feels the need to acquire it, there are many different strategies for doing so. Sometimes they borrow the idea / object / technique and give it a new name of their own; sometimes they borrow the idea / object / technique together with its name, which they may accept as is or which they may alter to their own taste and needs. "PK" has come into Chinese as a "letter word" (zìmǔ cí 字母词), "nerd" has entered Chinese directly as a borrowing, but also through various approximations and adaptations, while "geek" has been assimilated through partial and full transcription, plus outright borrowing. One thing is certain: words, ideas, objects, and techniques travel far and wide across the globe, leading to cross-fertilization and mutual enrichment of the cultures that belong to the human family.
[A tip of the hat to Sanping Chen and thanks to Matt Smith, Brendan O'Kane, David Lancashire, Nathan Hopson, Hiroko Sherry, Yunong Zhou, Melvin Lee, Liwei Jiao, Xu Wenkan, Zhenzhen Lu, Gianni Wan, Mandy Chan, Annie Chan, Rebecca Fu, Jing Wen, Sophie Wei, Wu Yue, Alan Chin, Tyler Cheung, Fan Jiayang, Cao Lin, Cheng Fangyi, Wu Yuchang, Chen Wenjie, Zōu Chénkē, Bob Bauer, Don Snow, and Summer Hu]