(1):

(n.) A pivoted tongue, or sliding bolt, on one part of a machine, adapted to fall into notches, or interdental spaces, on another part, as a ratchet wheel, in such a manner as to permit motion in one direction and prevent it in the reverse, as in a windlass; a catch, click, or detent. See Illust. of Ratchet Wheel.

(2):

(v. t.) To stop with a pawl; to drop the pawls off.