early 15c., "act of enjoying," from Old French fruition and directly from Late Latin fruitionem (nominative fruitio) "enjoyment," noun of action from past-participle stem of Latin frui "to use, enjoy" (from PIE root *bhrug- "to enjoy"). Sense of "act or state of bearing fruit," resisted by dictionary editors, is attested by 1885, from association with fruit (n.); figuratively in this sense from 1889.
It forms all or part of: brook (v.) "to endure;" defunct; fructify; fructose; frugal; fruit; fruitcake; fruitful; fruition; fruitless; frumentaceous; function; fungible; perfunctory; tutti-frutti; usufruct.
It is the hypothetical source of/evidence for its existence is provided by: Latin frui "to use, enjoy," fructus "an enjoyment, proceeds, fruit, crops;" Old English brucan "use, enjoy, possess," German brauchen "to use."
c. 1300, rejoisen, "to own (goods, property), possess, enjoy the possession of, have the fruition of," from Old French rejoiss-, present participle stem of rejoir, resjoir "gladden, rejoice," from re-, which here is of obscure signification, perhaps an intensive (see re-), + joir "be glad," from Latin gaudere "rejoice" (see joy).
From mid-14c. in a transitive sense of "make joyful, gladden." Intransitive meaning "be full of joy" is recorded from late 14c. Middle English also used simple verb joy "to feel gladness; experience joy in a high degree" (mid-13c.) and rejoy (early 14c.). Also in 15c.-16c. "to have (someone) as husband or wife, to have for oneself and enjoy." To rejoice in "be glad about, delight in" is from late 14c. Related: Rejoiced; rejoicing.