Where does “таинственность” come from?

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

таинственность (Russian): mystery

Definitions

  1. mystery

Ancestry of “таинственность”, step by step

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