: inflammation, edema, and subsequent obstruction of the larynx, trachea, and bronchi especially of infants and young children that is typically caused by a parainfluenza virus and is marked by episodes of difficult breathing and low-pitched cough resembling the bark of a seal
Middle English croupe, croup, borrowed from Anglo-French croupe (also continental Old French), probably going back to an Old Low Franconian outcome of Germanic *kruppa- "something rounded, bulge" — more at crop entry 1
Note: This etymology is traditional, and phonetically impeccable, though "hindquarters of an animal" is not among the many meanings attested in Germanic for this etymon. Compare group entry 1. See also croupier, crupper.
Noun (2)
noun derivative of croup "to cry hoarsely, croak" (now English regional and Scots), probably of imitative origin