ancillary

Synonym discussion

Sense: adjective/1

'Ancillary' describes something that supports a main activity or exists beside it in a less important position. It is fairly formal and common in business, law, education, and technical writing: 'ancillary services', 'ancillary staff'. 'Supplementary' is close, but it often suggests extra material added to complete something, such as a supplementary chapter or worksheet. 'Auxiliary' is more technical and often names a backup system, unit, or machine, as in an auxiliary engine. 'Secondary' mainly stresses lower rank or importance, and it does not always suggest active support. So a hotel may offer ancillary services, a textbook may include supplementary exercises, a boat may have an auxiliary motor, and a side issue in a debate may be secondary.

Common collocations

Etymology

Comes from Latin 'ancilla', meaning 'female servant'. In English, 'ancillary' first described something in a serving or helping position. Later, the word lost the idea of an actual servant and came to mean work, services, or items that support a main thing or stand in a secondary role.