Where does “infeminine” come from?

infeminine (English) comes from English feminine, from Middle English femynyne, from Old French feminin, from Latin femininus, from Latin -inus, from Proto-Italic -īnos, from Proto-Indo-European -iHnos, from Proto-Indo-European -no- — adjectival suffix.

Ancestry of “infeminine”, step by step

infeminine traces back through two separate lines of ancestry.

via English feminine

StepLanguageWordMeaning
1EnglishfeminineOf or pertaining to the female gender; womanly;...
2Middle Englishfemynynefemale of feminine sex or gender
3Old Frenchfeminin
4Latinfemininusfeminine; of or relating to the feminine gender
5Latin-inusOf or pertaining to; -ine
6Proto-Italic-īnosof/belonging to
7Proto-Indo-European-iHnosCreates adjectives of materials
8Proto-Indo-European-no-adjectival suffix

via English in

StepLanguageWordMeaning
1EnglishinUsed to indicate location, inclusion, or position...
2Middle EnglishinAny kind of accomodation; particularly; A home or...
3Old Englishinin; Alternative form of inn
4Proto-West Germanic*in
Every word from Proto-Indo-European -no-Every word from Latin -inusEvery word from Proto-Italic -īnos