Source : Webster's Revised Unabridged Dictionary (1913)

Bonus \Bo"nus\, n.; pl. {Bonuses}. [L. bonus good. Cf. {Bonny}.]
   1. (Law) A premium given for a loan, or for a charter or
      other privilege granted to a company; as the bank paid a
      bonus for its charter. --Bouvier.

   2. An extra dividend to the shareholders of a joint stock
      company, out of accumulated profits.

   3. Money paid in addition to a stated compensation.

Source : WordNet®

bonus
     n 1: anything that tends to arouse; "his approval was an added
          fillip" [syn: {fillip}]
     2: an additional payment (or other remuneration) to employees
        as a means of increasing output [syn: {incentive}]