In a French manner or style; characteristically in the way French people do things.
From 'French' with the adverb-forming suffix -ly. Parallel to other adverbs like 'Englishly' or 'Italianly,' though rarely used in contemporary English.
Even though 'frenchly' is grammatically perfect, we almost never say it—we'd rather say 'in a French way' instead, which shows that just because English can make a word doesn't mean people will actually use it!
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