noun one who, or that which, contributes aid or additional supplies; an assistant; an auxiliary.
2. subsidiary ·adj furnishing aid; assisting; auxiliary; helping; tributary; especially, aiding in an inferior position or capacity; as, a subsidiary stream.
3. subsidiary ·adj 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.