Definition of "hex"

(transitive) To cast a spell on (specifically an evil spell), to bewitch.  examples

An evil spell or curse.  examples

A witch.  examples

(rare) A spell (now rare but still found in compounds such as hex sign and hexcraft).

(computing, informal) Clipping of hexadecimal.  examples

A hexagonal space on a game board.  examples

(climbing) a hexagon-shaped item of rock climbing equipment intended to be wedged into a crack or other opening in the rock.  examples