noun
also packet ship
1. : a boat (as originally a fast sailing ship) chartered by a government to carry mail and dispatches
letters … conveyed by government packet boats or by ordinary sailing ship — Samuel Graveson
2.
a. : a river or coastal steamer usually of shallow draft carrying mail, passengers, and cargo on a regular run
took passage for Boston on the midweek packet boat — Kenneth Roberts
b. : a canalboat designed to carry passengers