"to raise frivolous objections, find fault without good reason," 1540s, from Middle French caviller "to mock, jest," from Latin cavillari "to jeer, mock; satirize, argue scoffingly" (also source of Italian cavillare, Spanish cavilar), from cavilla "jest, jeering," which is related to calumnia "slander, false accusation" (see calumny). Related: Caviller, cavilling.