ass from one's elbow etc, not know one's expr AmE vulg sl He doesn't know his ass from his elbow Он набитый дурак That old bastard don't know his ass from a hole in the ground Этот тип настоящий придурок
NOT KNOW ONE'S ASS FROM ONE'S ELBOW
Англо-русский перевод NOT KNOW ONE'S ASS FROM ONE'S ELBOW
Глазунов. New English-Russian dictionary of modern informal English. Англо-Русский новый словарь современного неформального английского языка. 2012