Why is the ninth month called September?
1540s, "daring, defiance, boasting," from French braverie, from braver "to brave" (see brave) or else from cognate Italian braveria, from bravare.
No Man is an Atheist, however he pretend it and serve the Company with his Braveries. [Donne, 1631]As a good quality, attested from 1580s. Meaning "fine clothes" is from 1560s and holds the older sense.
(Isa. 3:18), an old English word meaning comeliness or beauty.