Emily Dickinson Lexicon

BRAG, v.i. [W. bragiaw, to swell, to shoot up, to brag; brag, a sprouting, malt; bragu, to malt. It coincides with Dan. brager, to crackle, Gr. βραχω, Eng. to brag, and many other words signifying to break, or shoot forth. See Brave.]

To boast; to display one's actions, merits, or advantages ostentatiously; to tell boastful stories; followed by of; as, to brag of a good horse, or of a feat. – Sidney. Shak. To brag on, is vulgar; indeed the word itself is become low and is not to be used in elegant composition.