къртя

Etymology 1
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Verb

 * 1)  to break, to crack, to peck (with a tool)
 * 2)  to quarry (for minerals), to muck
 * 3)  to crack up, to break down, to get/develop crevice

Etymology 2
Probably onomatopoeic in nature. Most dictionaries do not formally distinguish it from Etymology 1.

Verb

 * 1)  to sleep deeply, to snooze