## thetetus

Proper noun

- A classical Greek mathematician, living
*circa*417–369 B.C., credited with proving that there are precisely five regular convex polyhedra. - A later middle dialogue of Plato concerning epistemology.
- A lunar impact crater 2·8 kilometres in depth and 25 kilometres in diameter, located southeast of the crater Cassini, near the eastern edge of Mare Imbrium, at coördinates 37·0° N, 6·0° E.

Origin

From Ancient Greek *Θεαίτητος* (Theaitētos); the mathematician is the eponym of the dialogue and the lunar crater.