enjoy v.

word-forming element meaning "in; into," from French and Old French en-, from Latin in- "in, into" (from PIE root *en "in"). Typically assimilated before -p-, -b-, -m-, -l-, and -r-. Latin in- became en- in French, Spanish, Portuguese, but remained in- in Italian.

Also used with native and imported elements to form verbs from nouns and adjectives, with a sense "put in or on" (encircle), also "cause to be, make into" (endear), and used as an intensive (enclose). Spelling variants in French that were brought over into Middle English account for parallels such as ensure/insure, and most en- words in English had at one time or another a variant in in-, and vice versa.

c. 1200, "feeling of pleasure and delight;" c. 1300, "source of pleasure or happiness," from Old French joie "pleasure, delight, erotic pleasure, bliss, joyfulness" (11c.), from Latin gaudia "expressions of pleasure; sensual delight," plural of gaudium "joy, inward joy, gladness, delight; source of pleasure or delight," from gaudere "rejoice," from PIE root *gau- "to rejoice" (cognates: Greek gaio "I rejoice," Middle Irish guaire "noble").

As a term of endearment from 1580s. Joy-riding is American English, 1908; joy-ride (n.) is from 1909.