(1):

(v. t.) The person or thing that promotes or helps in something done; a helper; an assistant.

(2):

(v. t.) A subsidy granted to the king by Parliament; also, an exchequer loan.

(3):

(v. t.) A pecuniary tribute paid by a vassal to his lord on special occasions.

(4):

(v. t.) An aid-de-camp, so called by abbreviation; as, a general's aid.

(5):

(v. t.) Help; succor; assistance; relief.

(6):

(v. t.) To support, either by furnishing strength or means in cooperation to effect a purpose, or to prevent or to remove evil; to help; to assist.