quail: Quail the bird [14] and quail ‘cower’ [15] are not related. The former comes via Old French quaille from medieval Latin coacula, which probably originated in imitation of the bird’s grating cry. It is not known for certain where the verb (which originally meant ‘decline, wither, give way’) came from, although some have linked it with another verb quail, now obsolete, which meant ‘curdle’. This came via Old French quailler from Latin coāgulāre, source of English coagulate. => coagulate
