1. (a.) Furnishing aid; assisting; auxiliary; helping; tributary; especially, aiding in an inferior position or capacity; as, a subsidiary stream.

2. (a.) of or pertaining to a subsidy; constituting a subsidy; being a part of, or of the nature of, a subsidy; as, subsidiary payments to an ally.

3. (n.) One who, or that which, contributes aid or additional supplies; an assistant; an auxiliary.

accessory accident accidental addendum addition additional adjunct adjuvant adscititious adventitious ancillary appendage appurtenance appurtenant ascititious assistant assisting auxiliary casual circumstantial collateral contingency contingent contributory dotal dower dowered dowry endowed extra fortuitous fostering happenstance helping incidental inessential instrumental invested mere chance ministerial ministering ministrant minor nonessential not-self nurtural nutricial other pensionary secondary serving stipendiary subordinate to subservient superadded superaddition superfluous supervenient supplement supplemental supplementary tributary unessential