free rider

noun4

1. •
   One who gets a free ride on a ship, or similar; one who rides on a means of transportation gratis.
2. •
   Someone who obtains goods or services legally without paying.

   • The store failed because all of the manager's friends were free riders who drove paying customers away.
3. •
   One who obtains benefit from a public good without paying for it directly.

   • A lighthouse is the classic example of a public good because it is difficult to prevent a ship (a free rider) from using it.
4. •
   A worker at an open shop who is able to enjoy the benefits negotiated by a union without being a member of the union.