know one's head from a hole in the ground
English
editVerb
editknow one's head from a hole in the ground (third-person singular simple present knows one's head from a hole in the ground, present participle knowing one's head from a hole in the ground, simple past knew one's head from a hole in the ground, past participle knowing one's head from a hole in the ground)
- Synonym of know one's ass from a hole in the ground