Source : Webster's Revised Unabridged Dictionary (1913)

Allowance \Al*low"ance\, n. [OF. alouance.]
   1. Approval; approbation. [Obs.] --Crabbe.

   2. The act of allowing, granting, conceding, or admitting;
      authorization; permission; sanction; tolerance.

            Without the king's will or the state's allowance.
                                                  --Shak.

   3. Acknowledgment.

            The censure of the which one must in your allowance
            o'erweigh a whole theater of others.  --Shak.

   4. License; indulgence. [Obs.] --Locke.

   5. That which is allowed; a share or portion allotted or
      granted; a sum granted as a reimbursement, a bounty, or as
      appropriate for any purpose; a stated quantity, as of food
      or drink; hence, a limited quantity of meat and drink,
      when provisions fall short.

            I can give the boy a handsome allowance.
                                                  --Thackeray.

   6. Abatement; deduction; the taking into account of
      mitigating circumstances; as, to make allowance for the
      inexperience of youth.

            After making the largest allowance for fraud.
                                                  --Macaulay.

   7. (com.) A customary deduction from the gross weight of
      goods, different in different countries, such as tare and
      tret.

Allowance \Al*low"ance\, v. t. [imp. & p. p. {Allowancing}.]
   [See {Allowance}, n.]
   To put upon a fixed allowance (esp. of provisions and drink);
   to supply in a fixed and limited quantity; as, the captain
   was obliged to allowance his crew; our provisions were
   allowanced.

Source : WordNet®

allowance
     n 1: an amount allowed or granted (as during a given period);
          "travel allowance"; "my weekly allowance of two eggs";
          "a child's allowance should not be too generous"
     2: a sum granted as reimbursement for expenses
     3: an amount added or deducted on the basis of qualifying
        circumstances; "an allowance for profit" [syn: {adjustment}]
     4: a permissible difference; allowing some freedom to move
        within limits [syn: {leeway}, {margin}, {tolerance}]
     5: a reserve fund created by a charge against profits in order
        to provide for changes in the value of a company's assets
        [syn: {valuation reserve}, {valuation account}, {allowance
        account}]
     6: the act of allowing; "He objected to the allowance of
        smoking in the diningroom"
     v : put on a fixed allowance, as of food