Definition of cheshire cat in English English dictionary
A fictional grinning cat, made popular by Lewis Carroll's Alice's Adventures in Wonderland
If someone is grinning like a Cheshire cat or like the Cheshire cat, they are smiling very widely. He had a grin on his face like a Cheshire Cat. a Cheshire Cat smile. a character in Alice's Adventures in Wonderland by Lewis Carroll, which disappears very slowly until only its big smile is left. People sometimes say someone is "grinning like a Cheshire cat" to mean that they have a big and rather silly smile on their face