One of the mysteries of the English language finally explained.
On the basis of or with respect to qualities, interests, or circumstances specific to a particular woman, rather than a general principle (in later use especially as a means of discrediting the woman concerned).
That addresses the characteristics or qualities of a specific woman rather than her argument or position, especially as a means of discrediting her.
Mid 19th century; earliest use found in The Quarterly Review. From classical Latin ad to + fēminam, accusative singular of fēmina woman, after ad hominem, with this being (either erroneously or facetiously) interpreted as a gender-specific term requiring a feminine analogue.
ad feminam/ˌad ˈfɛmɪnam/
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