AIDS, Engl. law. Formerly they were certain sums of money granted by the tenant to his lord in times of difficulty and distress, but, as usual in such cases, what was received as a gratuity by the rich and powerful from the weak and poor, was soon claimed as a matter of right; and aids became a species of tax to be paid by the tenant to his lord, in these cases: 1. To ransom the lord's person, when taken priisoner; 2. To make the lord's eldest son a knight; – 3. To marry the lord's eldest daughter, by giving her a suitable portion. The first of these remained uncertain; the other two were fixed by act of parliament at twenty shillings each being the supposed twentieth part of a knight's fee, 2 Bl. Com. 64.