gratuity

Concise Oxford English Dictionary © 2008 Oxford University Press:
gratuity /grəˈtjuːɪti/

▶noun (pl. gratuities)

• 1 formal a tip given to a waiter, porter, etc.

• 2 Brit. a sum of money paid to an employee at the end of a period of employment.

– origin C15 (denoting graciousness): from OFr. gratuité or med. L. gratuitas ‘gift’.