Cos'è fleet? Cos'è fleet? A number of warships operating together under one command.A group of vessels or vehicles, such as taxicabs or fishing boats, owned or operated as a unit.Moving swiftly; rapid or nimble. See Synonyms at fast1. Fleeting; evanescent.To move or pass swiftly.To fade out; vanish.Archaic To flow.Obsolete To drift.To cause (time) to pass quickly.Nautical To alter the position of (tackle or rope, for example).