Webster's Revised Unabridged Dictionary -- Volume AB

You speedy helpers . . .
Appear and aid me in this enterprise.
Shak.

Syn. -- To help; assist; support; sustain; succor; relieve; befriend; coöperate; promote. See Help.

Aid, n. [F. aide, OF. aïde, aïe, fr. the verb. See Aid, v. t.]

1. Help; succor; assistance; relief.

An unconstitutional mode of obtaining aid.
Hallam.

2. The person or thing that promotes or helps in something done; a helper; an assistant.

It is not good that man should be alone; let us make unto him an aid like unto himself.
Tobit viii. 6.

3. (Eng. Hist.) A subsidy granted to the king by Parliament; also, an exchequer loan.

4. (Feudal Law) A pecuniary tribute paid by a vassal to his lord on special occasions. Blackstone.

5. An aid-de-camp, so called by abbreviation; as, a general's aid.

-- Aid prayer (Law), a proceeding by which a defendant beseeches and claims assistance from some one who has a further or more permanent interest in the matter in suit.

-- To pray in aid, to beseech and claim such assistance.

Aid"ance (?), n. [Cf. OF. aidance.] Aid. [R.]

Aidance 'gainst the enemy.
Shak.

Aid"ant (?), a. [Cf. F. aidant, p. pr. of aider to help.] Helping; helpful; supplying aid. Shak.