Meaning

noun showy tropical tree or shrub native to Madagascar; widely planted in tropical regions for its immense racemes of scarlet and orange flowers; sometimes placed in genus Poinciana

adjective marked by ostentation but often tasteless

adjective elaborately or excessively ornamented

originBorrowed from French flamboyant (“flaming, wavy”), participle of flamboyer (“to flame”), from Old French flamboier, from flambe (“flame”). The architectural style derives its name from the flame-like shapes in the tracery.

Etymology from Wiktionary, CC BY-SA 3.0