Definition, Meaning & Synonyms
not-play-with-a-full-deck
idiom
/nɒt pleɪ wɪð ə fʊl dɛk/

Definition
To be mentally unstable or irrational.

Examples
After hearing his bizarre theories, I started to think he might not be playing with a full deck.
She said some strange things last night; I wonder if she’s not playing with a full deck.

Meaning
This phrase suggests that a person may not be thinking clearly or may be lacking in some mental faculties, akin to not having all the necessary cards in a deck for playing a game.

Synonyms
- not all there
- off one’s rocker
- not quite right