DETENT
Source: 567
De‐tent″ (?), n. [[F. détente, fr. détendre to unbend, relax; pref. dé- (L. dis- or de) + tendre to stretch. See Distend.]] (Mech.) That which locks or unlocks a movement; a catch, pawl, or dog; especially, in clockwork, the catch which locks and unlocks the wheelwork in striking.