The quality of being feminine; the state or condition of having feminine characteristics.
From 'feminine' plus the suffix '-ness,' which creates a noun from an adjective. This is a traditional English way to nominalize qualities, though 'femininity' is the standard modern form.
English speakers have multiple ways to express the same concept—'femininity,' 'feminilty,' and 'feminineness' all mean roughly the same thing, but we choose the shortest and most common one ('femininity') in everyday speech.
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