ancient activity

[DARRAN]

from which ancient activity does the phrase crestfallen come from ??

[gen2]

As an intelligent guess, may I suggest 'Male Chicken Fighting' (I cannot use the four-letter word for male chicken - this site won't let me).

[Clanad]

Actually, according to Word Origins, gen2 isn't that far afield...A "crest," of course, is the tuft or ridge of feathers or the fleshy formation found atop the heads of many kinds of birds (also called "combs" when sported by chickens). The word "crest" comes from the Latin "crista," meaning "tuft or plume." When birds that have crests are happy or self-confident (think roosters), they proudly raise their crests. When crested birds are angry or fearful, however, their crests fall in preparation for combat. Birds that are disappointed or depressed probably find their crests fallen as well, but poultry psychoanalysis is still a young art, so that's just my personal hypothesis...

[gen2]

Clanad, yes I read that too. DARRAN's question asked from which activity ... hence my (hopefully) intelligent guess of ****fighting.

[mrbatfink]

My theory would be from the days of knights fighting...

Knights usually wore there family crest (coat of arms). When a night went down his family (and possibly the knight if he still lived) would be crest-fallen.

Just my theory....

[Quizmonster]

The earliest use of of the word in English dates back to the late 16th century and quite clearly refers to a "....erel". (The missing four letters start with a 'c' and end with a 'k' with 'oc' between.)
Shakespeare used the word figuratively over a century later to refer to a person being 'downcast'. All a bit late for jousting knights, I suspect!
If it does refer to an 'ancient activity' rather than just a fact of avian life, I'd guess it is as Gen2 suggests. However, I know of no firm evidence that it is related to an activity.

[dtw]

Earliest OED citation, 1589, "O how meager and leane hee lookt, so creast falne, that his combe hung downe to his bill." ...supports the bird theory, doesn't it?

[Quizmonster]

That's exactly what I said in my opening paragraph above, Dtw, and that was the specific quote I based my answer on!