be one card short of a full deck

To be not very intelligent or of questionable mental capacity. This expression can appear in many different forms and variations (e.g., "a few sandwiches short of a picnic," "one brick short of a load.," etc.). He says he's going to start a business selling bees as pets—I think he may be one card short of a full deck. The new manager is nice enough, but he's one card short of a full deck, if you ask me.

See also: card, deck, full, of, one, short

Common Names:

Name	Pronounced	Usage
Erminlinda	-	Ancient Germanic
Shad (1)	-	Arabic
Valeriya	vah-LYE-ree-yah (Russian)	Russian, Ukrainian
Sigfrid (2)	-	Norwegian
Jeroboam	-	Biblical
Martha	MAHR-thə (English)	English, Swedish, Norwegian, Danish, Dutch, German, Greek, Biblical, Old Church Slavic, Biblical Lat