1630s, from adj. (mid-15c.), from M.L. allocate (the common first word of writs authorizing payment), imperative plural of allocare "allocate," from L. ad- "to" + locare "to place" (see locate).
c.1300, from O.Fr. alouer "approve," from L. allaudare, compound of ad- "to" + laudare "to praise," confused and merged in O.Fr. with alouer "assign," from L. allocare (see allocate). From the first word came the sense "permission based on approval," from the second the meaning preserved in allowance.