c.1600, "state in which supreme power rests in the people via elected representatives," from Middle French république (15c.), from Latin respublica (ablative republica) "the common weal, a commonwealth, state, republic," literally res publica "public interest, the state," from res "affair, matter, thing" + publica, fem. of publicus "public" (see public, adj.). Republic of letters attested from 1702.