An evil spell or curse.
A spell (now rare but still found in compounds such as hex sign and hexcraft).
A hexagonal space on a game board.
A witch.
a hexagon-shaped item of rock climbing equipment intended to be wedged into a crack or other opening in the rock.
To cast a spell on (specifically an evil spell), to bewitch.
A kiss on the cheek that signifies the death of the receiver, as delivered by a mob boss or one with such influence.
Something that may seem good and favourable but that actually brings ruin to hopes, plans, etc.