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
Randal	['rændl]
Herakleios	-	Ancient Greek
Hildebrand	HIL-de-brahnt (German)	German (Archaic), Ancient Germanic
Kendal	['kendəl]
Jet	-	Dutch
Florentino	-	Spanish