In a manner that follows proper form or ceremony; formally or methodically.
From form + -ly (Old English -lice, adverbial suffix). This archaic or rare formation mirrors standard adverb construction, though 'formally' is the standard modern equivalent.
Formly is mostly obsolete, replaced by 'formally,' but it shows how English speakers once tried different ways to make adverbs—language naturally selected the smoother-sounding versions, which is why we don't hear formly anymore.
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