'Stowaway' definitions:

Definition of 'stowaway'

(from WordNet)
noun
A person who hides aboard a ship or plane in the hope of getting free passage

Definition of 'Stowaway'

From: GCIDE
  • Stowaway \Stow"a*way`\, n. One who conceals himself board of a vessel about to leave port, or on a railway train, in order to obtain a free passage. [1913 Webster]