The Cheshire cat grin is “a smile with far too many teeth on display, where the mouth doesn’t match up with the eyes, going practically from ear to ear,” according to TV Tropes.

It's the same thing for a "Cheshire cat smile" eclipse, made famous by the Cheshire cat character in "Alice in Wonderland," where the cartoon cat shows a perfect smile − just teeth.

Some people liken this peculiar phase of the sun and moon as a "Cheshire cat smile" or a "horizontal smiley face" shape. In a March 1, 2025, Space.com story, ...