Ram

1. A weapon consisting of an underwater prolongation of the bow of a vessel to form an armored beak, intended to be driven into the hull of an enemy vessel in order to puncture the hull and disable or sink that vessel.
2. An armored warship of the second half of the 19th century designed to use such a weapon as her primary means of attack.
3. To intentionally collide with another vessel with the intention of damaging or sinking her.
4. To accidentally collide bow-first with another vessel.