This morning on the radio, I heard this from Therese Madden of FIT:
"We are Food Justice…"
That's just one of the chants heard on the lawn outside of the Independence Visitor Center on a recent Saturday afternoon. The hot sun did nothing to damper the enthusiasm of the 120 young people, mostly between the ages of 15 and 20.
This makes perfect sense, in that the first meaning of damper as a noun is "Something that damps or depresses the spirits", according to the OED.
But even though English is generally happy to uses nouns as verbs, there isn't a very well-established verb damper. And so instead, the common collocation "dampen <someone's> enthusiasm" has always used the verb dampen "To dull, deaden, diminish the force or ardour of, depress, deject".
Still, there are plenty of examples of enthusiasm-dampering on the web, e.g.
Last week's warm-up didn't damper the enthusiasm for the 5th Annual U.P. Pond Hockey Championship
Yet it did nothing to damper the enthusiasm among those in attendance.
“We don't want to damper the enthusiasm of the pool commission,” said Edelmayer, the township board's liaison to the commission.
The hot sun did nothing to damper the enthusiasm of the 120 young people, mostly between the ages of 15 and 20.
We can also find a few in the media outlets indexed by Google News:
The crowd was great for the Justin Moore concert and the rain didn't seem to damper the enthusiasm.
But the fact Musical Romance had to settle for second money didn't damper the enthusiasm of Kaplan, who couldn't have been more pleased with the performance.
Rain didn’t damper the enthusiasm of car owners and car lovers Sunday at the 39th Concours d’Elegance, presented by The Rotary Club of Forest Grove.
And even in Google Books:
Foster's attacks elicited little reaction and failed to damper the enthusiasm of league officials …
Poorly designed programs may damper the enthusiasm of all parties involved toward future mentorships.
There are no time-honored precedents, rules and regulations governing the making of motion pictures to damper the enthusiasm of a pioneering spirit or a man with new ideas.
But the COCA corpus has no examples of dampering enthusiasm, compared to 23 of dampening enthusiasm; the BNC has 13 examples of dampening and none of dampering.
The NYT index (since 1851) has 739 examples of the specific string "dampen the enthusiasm", compared to two of "damper the enthusiasm":
Connor Ennis, "Road Trip, Part 5", 10/18/2007: And of course, we can’t forget about Illinois, whose balloon we saw burst in Iowa City last weekend. Though that didn’t damper the enthusiasm the family of quarterback Juice Williams, who wear their pride in the stands and explain the heavy meaning behind his nickname.
John Branch, "Under the wigs, Dogers face a marketing test", 5/9/2009: Somehow, the fact that he [Manny Ramirez] was caught did little to damper the enthusiasm, at least inside Dodger Stadium.
Since this is just a matter of swapping suffixes between dampen and damper, it's not a very poetic eggcorn, not in the league of youthamism for euphemism, or having something down packed for down pat. But it's still an interesting example of the kind of meme-pool variation that sometimes turns into language change.