word of the day - ancillary

an·cil·lar·y (ns-lr) KEY
ADJECTIVE:
Of secondary importance: "For Degas, sculpture was never more than ancillary to his painting" (Herbert Read).
Auxiliary; helping: an ancillary pump.
NOUN: pl. an·cil·lar·ies
Something, such as a workbook, that is subordinate to something else, such as a textbook.
Archaic A servant.

ETYMOLOGY: From Latin ancilla, maidservant, feminine diminutive of anculus, servant; see kwel- 1 in Indo-European roots