The term "depth bomb" refers to a type of explosive device that is designed to be dropped into the water to attack submarines. There are many synonyms that can be used to describe this type of weapon, including anti-submarine grenade, depth charge, underwater mine, and sonobuoy. Each of these terms is used to describe a slightly different type of weapon, but all are designed to attack submarines and other underwater targets. Whether you are a military historian or simply interested in the history of underwater warfare, knowing the different synonyms for the word "depth bomb" can be useful for understanding the types of weapons that were used in naval battles.