Where does “якобы” come from?

якобы (Russian) comes from Russian бы́, from Old East Slavic бꙑ, from Proto-Slavic *by.

якобы (Russian): allegedly, supposedly

Definitions

  1. allegedly, supposedly

Ancestry of “якобы”, step by step

якобы traces back through two separate lines of ancestry.

via Russian бы́

StepLanguageWordMeaning
1Russianбы́—
2Old East Slavicбꙑ—
3Proto-Slavic*by—

via Russian я́ко

StepLanguageWordMeaning
1Russianя́коlike, as
Every word from Proto-Slavic *by →Every word from Old East Slavic бꙑ →Every word from Russian бы́ →