The definition of a lantern jaw is a lower jaw that sticks out further than the upper jaw, or a long thin jaw that often makes a person look too thin.
An example of a lantern jaw is an underbite.
- a projecting lower jaw
- [pl.] long, thin jaws, with sunken cheeks, that give the face a lean, gaunt appearance
Origin of lantern jawfrom resemblance to the early lantern with long sides of thin, concave horn
- A lower jaw that protrudes beyond the upper jaw.
- A long, thin jaw that gives the face a gaunt appearance.