Where does “pseudo-passive” come from?

pseudo-passive (English) comes from English passive, from Middle English passyf, from French passif, from Latin passivus, from Latin -īvus, from Proto-Indo-European -iHwós, from Proto-Indo-European -wós — Creates adjectives from verb stems.

Ancestry of “pseudo-passive”, step by step

pseudo-passive traces back through two separate lines of ancestry.

via English passive

StepLanguageWordMeaning
1EnglishpassiveBeing subjected to an action without producing a...
2Middle Englishpassyfpassive unreactive, inactive
3Frenchpassifthe passive voice; liability; passive
4Latinpassivussubject to passion or emotion; passive
5Latin-īvusAdjective suffix
6Proto-Indo-European-iHwós
7Proto-Indo-European-wósCreates adjectives from verb stems

via English pseudo

StepLanguageWordMeaning
1EnglishpseudoAn intellectually pretentious person; a...
2Englishpseudo-False, not genuine, fake
3Ancient Greekψευδήςlying, false, untrue; deceived, beguiled
4Ancient Greek-ήςadjective suffix
5Proto-Indo-European-ēsPrimarily forms adjectival bahuvrīhi compounds
6Proto-Indo-European-ess
7Proto-Indo-European-osCreates action nouns or result nouns from verbs;...
Every word from Proto-Indo-European -wósEvery word from Latin -īvusEvery word from Latin passivus