gra·tu·i·ty 
(grə-tĭ-tē, -ty-)
(grə-tĭ-tē, -ty-)n. pl. gra·tu·i·ties
A favor or gift, usually in the form of money, given in return for service.
[French gratuité, from Old French gratuite, from Medieval Latin grātuītās, probably from Latin grātuītus, voluntary; see GRATUITOUS.]
- interne
- interne
- internecine
- internee
- internet
- internetwork
- interneuron
- interneuronal
- internist
- internment
- internodal
- internode
- inter nos
- internship
- internuclear
- internuncial
- internuncially
- internuncio
- interoceptive
- interoceptor
- interoffice
- interoperability
- interoperable
- interpeduncular
- interpenetrate