Definify.com
Webster 1913 Edition
Aid
Aid
,Verb.
 T.
 [
imp. & p. p. 
Aided
; p. pr. & vb. n. 
Aiding
.] [F. 
aider
, OF. aidier
, fr. L. adjutare 
to help, freq. of adjuvare 
to help; ad 
+ juvare 
to help. Cf. Adjutant
.] To support, either by furnishing strength or means in coöperation to effect a purpose, or to prevent or to remove evil; to help; to assist. 
You speedy helpers . . . 
Appear and
Appear and
aid 
me in this enterprise. Shakespeare
Syn. – To help; assist; support; sustain; succor; relieve; befriend; coöperate; promote. See 
 Help
. 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.
 Webster 1828 Edition
Aid
AID
,Verb.
T.
  To help; to assist; to support, either by furnishing strength or means to effect a purpose, or to prevent or remove evil.
AID
,Noun.
  1.
  Help; succor; support; assistance.2.
  The person who aids or yields support; a helper; an auxiliary; also the thing that aids or yields succor.3.
  In English law, a subsidy or tax granted by parliament, and making a part of the king's revenue.In France, aids are equivalent to customs, or duties on imports and exports.
4.
  In England, a tax paid by a tenant to his lord; originally a mere gift, which afterwards became a right demandable by the lord.  the aids of this king were chiefly three.1.
  To ransom the lord when a prisoner.2.
  To make the lord's eldest son a knight.  3.
  To marry the lord's eldest daughter.5.
  An aiddecamp, so called by abbreviation.6.
  To pray in aid, in law, is to call in a person interested in a title, to assist in defending it.  Thus a tenant for life may pray in the aid of him in remainder or reversion; that is, he may pray or petition that he may be joined in the suit to aid or help maintain the title.  This act or petition is called aid-prayer.Court of aids, in France, is a court which has cognizance of causes respecting duties or customs.