Other forms: battleships
A battleship is a very large, seagoing military vessel. A battleship is prepared for war, being protected by heavy armor and equipped with guns.
Today's modern military doesn't often use battleships — you're more likely to find a battleship in a harbor being explored by tourists. In the 19th and early 20th centuries, battleships were the most modern, powerful kind of boat on the water, and they were used during both World Wars by various countries' navies. The game Battleship, which shares a name with these warships, has been around in one form or another since the 1930s.