vail

(transitive, obsolete) To lower, let fall; to allow or cause to sink.

(transitive, vexillology) To lower or “dip” a carried flag or banner in a salute by a forward reducing of the angle of the pike/flagstaff with respect to the ground; in extreme instances, as when saluting a monarch, both the banner and the finial of the pike are allowed to rest upon the ground.

(intransitive, obsolete, nautical) To lower a sail, in salute or otherwise.

(transitive, obsolete) To remove as a sign of deference, as a hat.

(intransitive, obsolete) To pay homage, bow, submit, defer (to someone or something); to yield, give way (to something).