Proto-IE: *kraip-/-ei-
Meaning: to bend, to hurry, etc.
Old Greek: krai̯pnó- 'swift, rushing' Hom.+, krai̯pálǟ f. 'drinking-bout; intoxication; drunken headache'
Russ. meaning: гнуть(ся), делать поспешно, etc.
References: Fraenkel 292 (differently in Pok.)