What does "trident" mean?

Trident: (Rom. Antiq.) A three-pronged spear or goad, used for urging horses; also, the weapon used by one class of gladiators.

Additional senses

  1. 2.A three-pronged fish spear.
  2. 3.(Geom.) A curve of third order, having three infinite branches in the direction and a fourth infinite branch in the opposite direction. Trident bat (Zoöl.), an Asiatic rhinolophid bat (Triænops Persicus), having the nose membrane in the shape of a trident.
  3. 4.Having three teeth or prongs; tridentate.

Sources