stowaway

noun

1. A person who hides on board a ship, train, etc. so as to get a free passage.

   ““Oh, I don't mind 'em, sir,” said Archy; “I knew it all before now. Didn't I hear 'em in the hold? And didn't I tell Cabaco here of it? What say ye, Cabaco? They are stowaways, Mr. Flask.””

   “In every sense of the expression he is ‘on deck’; but my Jim, for the most part, skulked down below as though he had been a stowaway.”

   “One explanation came to me, and I leaped at it—the possibility of a stowaway hidden in the hold, some maniacal fugitive who had found in the little cargo boat’s empty hull ample room to hide.”

   “My client is an infant, a poor foreign immigrant who started scratch as a stowaway and is now trying to turn an honest penny.”