Where does “основательно” come from?

основательно (Russian) comes from Russian основа́тельный, from Russian основа́ть — to found, establish.

основательно (Russian): thoroughly, well; short neuter singular of...

Definitions

  1. thoroughly, well; short neuter singular of...

Ancestry of “основательно”, step by step

StepLanguageWordMeaning
1Russianоснова́тельныйwell-grounded, well-founded
2Russianоснова́тьto found, establish
Every word from Russian основа́тьEvery word from Russian основа́тельный