enjoy: [14] Originally, enjoy was used intransitively in English, rather as in the modern American Yiddish-influenced injunction ‘Enjoy!’: ‘Yet he never enjoyed after, but in conclusion pitifully wasted his painful life’, Robert Laneham 1549. However, by the end of the 16th century the transitive sense ‘take pleasure in’ had virtually taken over the field. The word probably comes from Old French enjoïr, a compound formed from the prefix en- ‘in’ and joir ‘rejoice’, which in turn came from Latin gaudēre (ultimate source of English joy).
Old French did have another, similar verb, however, enjoier (formed from the noun joie), which probably also played a part in the English acquisition. => joy
late 14c., "rejoice, be glad" (intransitive), from stem of Old French enjoir "to give joy, rejoice, take delight in," from en- "make" (see en- (1)) + joir "enjoy," from Latin gaudere "rejoice" (see joy); Sense of "have the use or benefit of" first recorded early 15c. (replacing Old English brucan, for which see brook (v.)).
Transitive meaning "take pleasure in" is mid-15c. In modern use it has a tendency to lose its connection with pleasure: newspaper photo captions say someone enjoys an ice cream cone, etc., when all she is doing is eating it, and Wright's "English Dialect Dictionary" (1900) reports widespread use in north and west England of the phrase to enjoy bad health for one who has ailments. Meaning "have sexual relations with" (a woman) is from 1590s. Related: Enjoyed; enjoys; enjoying. To enjoy oneself "feel pleasure or satisfaction in one's mind" attested by 1708.