not know one’s ass from a hole in the ground

tv. not to be knowledgeable; not to be alert and effective. (Usually objectionable.) That stupid son of a bitch doesn’t know his ass from a hole in the ground.

Common Names:

Name	Pronounced	Usage
Alyce	AL-is	English
Griselda	gri-ZEL-də (English)	English, Scottish, Spanish, Literature
Squires	['skwaiəz]
Murugan	-	Hinduism, Tamil
Nigellus	-	English (Archaic)
Launce	-	Literature