Where does “убывание” come from?

убывание (Russian) comes from Russian убыва́ть, from Russian убы́ть, from Russian быть, from Old East Slavic бꙑти, from Proto-Slavic *byti, from Proto-Balto-Slavic bū́ˀtei, from Proto-Indo-European bʰuH- — to become, grow, appear.

убывание (Russian): decrease, reduction, waning action or result

Definitions

  1. decrease, reduction, waning action or result

Ancestry of “убывание”, step by step

StepLanguageWordMeaning
1Russianубыва́тьto diminish, to decrease; (water) to become lower, to subside, to go down; (moon) to wane, to be on the wane
2Russianубы́тьto diminish, to decrease; (water) to become lower, to subside, to go down; (moon) to wane, to be on the wane
3Russianбытьto be
4Old East Slavicбꙑтиto be
5Proto-Slavic*byti
6Proto-Balto-Slavicbū́ˀteito be
7Proto-Indo-EuropeanbʰuH-to become, grow, appear
Every word from Proto-Indo-European bʰuH-Every word from Proto-Balto-Slavic bū́ˀteiEvery word from Proto-Slavic *byti