1610s, "doing good, charitable through good will," probably from beneficence on model of magnificent, etc. The Latin adjective is beneficus.
Entries linking to beneficent
beneficence n.
"quality of being beneficent, kind, or charitable, practice of doing good," mid-15c., from Latin beneficentia "kindness, generosity," from beneficus "generous, kind, benevolent, obliging," from bene- "good, well" (see bene-) + -ficus "doing," from -ficere, combining form of facere "to do, to make" (from PIE root *dhe- "to set, put"). Related: Beneficency.