Motherships is a term mostly used in sci-fi and space movies to refer to a large spacecraft or vessel that carries smaller ones. However, there are other synonyms one can use instead of motherships. Some of the synonyms include "carrierships" which simply means a ship that carries other ships, "flagships" which is often used for the leading or premier ship in a fleet. Other synonyms can also include "command ships," "leviathan," and "capital ships." While some of these alternatives might not precisely imply the enormous size of a mothership, they still convey the concept of a ship carrying other ships.