not playing with a full deck

not playing with a full deck

Meaning

• not mentally sound
• stupid, dimwitted
• crazy or mentally deranged
• not very intelligent or bright
• mentally deficient

Example Sentences

1. With the number of silly remarks he comes up with, I wonder if he's not playing with a full deck.
2. He may be an influential person, but some of the things he does gives the impression that he is not playing with a full deck.
3. He keeps talking to himself. I think he's not playing with a full deck.
4. That scientist is considered to be a genius in his field, but with some of the antics he's up to at the university, it looks like he's not playing with a full deck.
5. The new teacher doesn't seem to know what he's teaching. He's not playing with a full deck.
6. He is a nice person, but with some of the foolish things he does, I think he's not playing with a full deck.

Origin

The phrase is one of the many derogatory ones that originated in America in the 1980s. The implication of the insult is that the person has some part of the brain missing. Deck is a reference to a deck of cards.