The quality of being beautifully or elegantly formed; handsomeness or shapeliness (archaic).
From Latin formosus, 'beautiful' + -ity (Latin -itas, indicating abstraction into a quality). This follows classical patterns for converting adjectives into abstract nouns.
Formosity is so rare that searching historical texts reveals almost nothing—it's the kind of word that probably existed in theory (Latin formositas) but never really took off in English, lost to simpler synonyms like 'beauty.'
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