c. 1300, "to blossom, grow" (intransitive), from Old French floriss-, stem of florir "to blossom, flower, bloom; prosper, flourish," from Latin florere "to bloom, blossom, flower," figuratively "to flourish, be prosperous," from flos "a flower" (from PIE root *bhel- (3) "to thrive, bloom"). Metaphoric sense of "thrive" is mid-14c. in English. Transitive meaning "brandish (a weapon), hold in the hand and wave about" is from late 14c. Related: Flourished; flourishing.