AIDS (Auxilia), a pecuniary tribute under the feudal system, paid by a vassal to his lord on particular occasions; originally a voluntary grant which in process of time became exigible as a right. The aids of this kind were chiefly three, viz. :—1 st , When the lord made his eldest son a knight; 2 d , To provide a dower when he gave his eldest daughter in marriage; 3 d , To ransom the person of the lord when taken prisoner. The amount of the first two was definitely fixed by 3 Ed. L, c. 36, but that of the last was of course uncertain. The right of levying aids was abolished by 12 Car. II., c. 24.