Source : Webster's Revised Unabridged Dictionary (1913)

Gratuity \Gra*tu"i*ty\, n.; pl. {Gtratuities}. [F. gratuit['e],
   or LL. gratuitas.]
   1. Something given freely or without recompense; a free gift;
      a present. --Swift.

   2. Something voluntarily given in return for a favor or
      service, as a recompense or acknowledgment.