1832, originally in reference to a 15c.-16c. architectural style with wavy, flame-like curves, from French flamboyant "flaming, wavy," present participle of flamboyer "to flame," from Old French flamboiier "to flame, flare, blaze, glow, shine" (12c.), from flambe "a flame, flame of love," from flamble, variant of flamme, from Latin flammula "little flame," diminutive of flamma "flame, blazing fire" (from PIE root *bhel- (1) "to shine, flash, burn"). Extended sense of "showy, ornate" is from 1879. Related: Flamboyantly.