Where does “взаимность” come from?

взаимность (Russian) comes from Russian -ость, from Proto-Slavic -ostь — Used with adjectival stems to form abstract...

взаимность (Russian): reciprocity, mutuality

Definitions

  1. reciprocity, mutuality

Ancestry of “взаимность”, step by step

StepLanguageWordMeaning
1Russian-ость-ness, -ity
2Proto-Slavic-ostьUsed with adjectival stems to form abstract...
Every word from Proto-Slavic -ostь →Every word from Russian -ость →