Where does “основательность” come from?

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

основательность (Russian): thoroughness; soundness, well-foundedness

Definitions

  1. thoroughness; soundness, well-foundedness

Ancestry of “основательность”, 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 →