A swaggering bully; a cowardly boaster who blows his own trumpet. Sir Walter Scott uses the word for finery, especially for the gold chains worn by military men, common in Spain amongst the conquerors of the New World. (Spanish, fanfarron, a bully; French, fanfare, a flourish of trumpets, or short piece of military music performed by brass instruments and kettledrums.)
“ `Marry, hang thee, with thy fanfarona about thy neck!'said the falconer.” —Scott: The Abbot. cxvii.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894