Proto-IE: *k(ʷ)ert-, *g(ʷ)-
Meaning: den
Old Indian: kartá- m. `hole, cavity', kŕ̥tā f. `abyss', kāṭá- m. `deepness, hole, well', gárta- m. `hollow, hole, cave'
Russ. meaning: нора
References: WP II 573 f
Comments: [Except for gárta-, all very probably < *kert- 'cut']