There are various synonyms for the word "a bomb" that can be used to describe different kinds of explosives. For example, "an explosive" is a general term that can refer to any substance that can be detonated to cause an explosion. "A grenade" is a small bomb that can be thrown by hand, whereas "a landmine" is usually buried in the ground and detonates when pressure is applied to it. "A missile" is a bomb that is launched from a vehicle, plane, or ship, and "a nuclear bomb" is a particularly powerful and destructive type of weapon that uses nuclear fission or fusion to release a massive amount of energy.