verb

• (intransitive) To waste away; to fade, to wither.
• (transitive, now rare) To daunt or frighten (someone).
  "Death dvvels vvithin vs, and if gentle Peace / Diſcend not ſoone, our ſorrovves to ſurceaſe, / Latium (alreadie quaild) vvill be deſtroyd."
• (intransitive) To lose heart or courage; to be daunted or fearful.
  "Though George had stopped in his sentence, yet, his blood being up, he was not to be cowed by all the generations of Osborne; rallying instantly, he replied to the bullying look of his father, with another so indicative of resolution and defiance, that the elder man quailed in his turn, and looked away."
• (intransitive) Of courage, faith, etc.: to slacken, to give way.
  "Therewith his ſturdie corage ſoone was quayd, / And all his ſences were with ſuddein dread diſmayd."

noun

• (uncountable) The meat from this bird eaten as food.
• (obsolete) A prostitute.
  "Her's Agamemnon, an honeſt fellow inough and one that loues quailes, but hee has not ſo much braine as eare-wax, […]"

verb

• (obsolete) To curdle or coagulate, as milk does.
  "[Laser is given] to such as haue supped off and drunk quailed milke, that is cluttered within their stomack."