n. & v.
n. 1 a set of teeth on the edge of a bar or wheel in which a device engages to ensure motion in one direction only. 2 (in full ratchet-wheel) a wheel with a rim so toothed.
v. (ratcheted, ratcheting) 1 tr. a provide with a ratchet. b make into a ratchet. 2 tr. & intr. move as under the control of a ratchet.
[ F rochet blunt lance-head, bobbin, ratchet, etc., prob. ult. f. Gmc ]