noun

1. a toothed wheel (in full ratchet wheel) or bar whose teeth slope in one direction so as to catch and hold a pawl, which thus prevents backward movement
2. such a pawl
3. such a wheel (or bar) and pawl as a unit: used in some wrenches, screwdrivers, etc. to allow motion in only one direction

Etymology: earlier rochet < Fr, lance head, distaff < It rocchetto, bobbin, spindle, dim. of rocca, distaff < Goth *rukka, akin to OHG roccho, spindle, distaff < IE base *ruk(k)-, spun yarn

transitive verb, intransitive verb