In a flatulent manner; with excessive gas or wind; in a pretentious or pompous way.
From 'flatulent' + '-ly' (the adverbial suffix), creating an adverb from the adjective 'flatulent'.
Using an adverb form of such a bodily-function word is delightfully awkward—it forces you to describe pompous speech as if someone is literally speaking in a physically inflated manner!
Complete word intelligence in one call. Free tier — 50 lookups/day.