chap·fall·en \ˈchapˌ- also -ä-\adjective orchop·fall·en\ˈchäpˌ-\ Etymology:chap (V)or chop (IV) + fallen 1.: having the lower jaw hanging loosely < a tired and chapfallen hound > 2.: dejected, depressed < sallied forth … with an air quite desolate and chapfallen — Washington Irving >