1660s, "subservient, subordinate," from Latin ancillaris "relating to maidservants," from ancilla "handmaid," fem. diminutive of anculus "servant," literally "he who bustles about," from root of ambi- "about" (see ambi-) + PIE *kwol-o-, from root *kwel- (1) "move round, turn about, be much about" (see cycle, n.).