Trident

A kind of scepter or spear with three prongs, -- the common attribute of Neptune.

A three-pronged spear or goad, used for urging horses; also, the weapon used by one class of gladiators.

A three-pronged fish spear.

A curve of third order, having three infinite branches in one direction and a fourth infinite branch in the opposite direction.

Having three teeth or prongs; tridentate.