I don't agree with the derivation given to this word. Chap=chop=chopfallen what's that about?
I think it might be derived from the word "shap" which means crest in English and is used to descibe hills mostly in northen England. Therefore Chap=shap=shapfallen=crestfallen.

>what's that about?

chap = (lower) jaw [Found first in the middle of the 16th c.; the variant chop is quoted from the Scottish poet Dunbar c 1500, and is now more usual in certain senses.]

hit him right in the chops

I not arguing that chap does not mean chop per se, simply that chap does not mean chop in chapfallen. Chap/chop/jaw prefixing fallen does not sensibly mean crestfallen. Therefore I hypothesied that this version of chap could have come from shap, which does mean crest i.e. c(s)hapfallen.

I,too, connon (and welcome! ) thought immediately of crestfallen and noted that I never heard AWAD's chap- or chop- derivations for this. Curious.

but the original meaning isn't crestfallen. here is OED2:
1. With the chap or lower jaw hanging down, as an effect of extreme exhaustion or debility, of a wound received, or esp. of death.

1598 GERARD Herbal I. i. 3 Beasts that be chap-fallen through long standing in pound. 1609 Ev. Woman in Hum. I. i. in Bullen O. Pl. IV, Her tung..wagges within her chap-faln jawes. 1621 FLETCHER Wild-G. Chase IV. iii, Till they be chap-fall'n, and their tongues at peace, Nail'd in their coffins. a1809 H. COWLEY Bold Stroke 26 That plump face of yours will be chap-fallen I believe. 1842 TENNYSON Vision of Sin iv. 110 Trooping from their mouldy dens The chap-fallen circle spreads.



b. Said of the mouth-piece of a helmet.

a1700 DRYDEN (J.) A chapfaln beaver loosely hanging by The cloven helm.



2. fig. Dejected, dispirited; crest-fallen.

1608 DAY Hum. out of Br. I. i. (1881) 6, I woulde poure Spirit of life..Into the iawes of chap-falne schollership. a1651 CLEVELAND To Mrs. K.T. Poems 16 The Chap~falne Puritan. 1794 WOLCOTT (P. Pindar) Rights of Kings Wks. III. 37 But, if his Nymph unfortunately frowns, Sad, chap fall'n, lo! he hangs himself, or drowns! 1881 BESANT & RICE Chapl. Fleet I. iv. (1883) 37 His clerk..stood with staring eyes and open mouth, chap-fallen and terrified.


note that the citations for the fig. senses usu. relate to fallen jaws.

Anu is just following OED2 (and W3, for that matter).