- trepidation
- 1605, from L. trepidationem (nom. trepidatio) "agitation, alarm, trembling," noun of action from pp. stem of trepidare "to tremble, hurry," from trepidus "alarmed, scared," from PIE *trep- "to shake, tremble" (cf. Skt. trprah "hasty," O.C.S. trepetati "to tremble"), related to *trem- (see tremble).