Beneficiary
early 17th century: from Latin beneficiarius, from beneficium (see benefice).
wiktionary
From Latin beneficiarius(“enjoying a favor, granted a privilege”) from beneficium(“benefit”), perhaps via or influenced by French bénéficiaire(“beneficiary”). Indirectly, by way of the etymology of the Latin word beneficium, the English word beneficiary ultimately has the same origin as the English word benefactor, its near antonym.
etymonline
beneficiary
1610s (n.) "one who receives profits or advantages," 1620s (adj.) "connected with the receipt of profits or advantages," probably via French bénéficiaire, from Latin beneficiarius "enjoying a favor, privileged," from beneficium "a favor, service, generosity, kindness, benefit," from beneficus "generous, kind, benevolent, obliging," from bene- "good, well" (see bene-) + -ficus "making, doing," from -ficere, combining form of facere "to do, to make" (from PIE root *dhe- "to set, put").