A person who hides on a ship, airplane, or train to travel without paying or being seen.
Stowaways are usually thought of as sneaky or adventurous, but also as breaking the rules.
Examples:
The stowaway was found hiding in the cargo hold.
The captain found a stowaway on the ship.
The stowaway snuck onto the plane without anyone seeing.
The stowaway thought he could hide in the big box, but he was found.
The stowaway traveled all the way to the new land without anyone knowing.
The stowaway was very scared when they found him hiding.