Also found in: Thesaurus, Legal, Financial.
1. Serving to assist or supplement; auxiliary.
2. Secondary in importance; subordinate.
3. Of, relating to, or of the nature of a subsidy.
n. pl. sub·sid·i·ar·ies
1. One that is subsidiary to another.
2. A subsidiary company.
3. Music A theme subordinate to a main theme or subject.
[Latin subsidiārius, from subsidium, support; see subsidy.]
sub·sid′i·ar′i·ly (-âr′ə-lē) adv.