hitchhiker

noun

1. A person or thing that hitchhikes.

   “It's a rough trip no matter how you come, for these washboard roads will loosen up even brandnew cars pretty fast; and hitchhikers always find the going bad.”

2. An item attached to a travel bug and hidden in a geocache to be found and transported to other caches or around the world.
3. A dance move in which the dancer mimics the motions of someone thumbing a ride.
4. (informal)A bur that attaches and clings to clothing, or a bur-bearing plant.
5. An advertisement at the end of a programme.

   “[…] and networks have taken steps to modify or eliminate the bunching of spots and commercials between programs which results from the use of hitchhikers and cowcatchers.”