"a boast, boastful talk, bluster," 1709, from French gasconade (see Gascon + -ade); from gasconner (16c.) "to boast, brag," literally "to talk like a Gascon." As a verb in English from 1727.
Entries linking to gasconade
Gascon
"native of Gascony," late 14c., from French Gascon, from Vulgar Latin *Wasco, from Latin Vasco, singular of Vascones, the name of the ancient inhabitants of the Pyrénées (see Basque). Among the French, proverbially a boastful people, hence gasconade (n.), "bragging talk" (1709).
-ade
word-forming element denoting an action or product of an action, via French, Spanish, or Italian, ultimately from Latin -ata, fem. past-participle ending used in forming nouns. The usual form in French is -ée. The parallel form, -ade, came into French about the 13c. via southern Romanic languages (Spanish, Portuguese, and Provençal -ada, Italian -ata), hence grenade, crusade, ballad, arcade, comrade, balustrade, lemonade, etc.
This foreign suffix ade has been so largely imported, and at a time when the French language had still a certain plastic force, that it has been adopted as a popular suffix, and is still employed to form a crowd of new words, such as promenade, embrassade, glissade, bourrade, &c. [Brachet, "Etymological Dictionary of the French Language," Kitchin transl., Oxford, 1882]
Latin -atus, past-participle suffix of verbs of the 1st conjugation, also became -ade in French (Spanish -ado, Italian -ato) and came to be used as a suffix denoting persons or groups participating in an action (such as brigade, desperado).