royalty

Definition from Nolo’s Plain-English Law Dictionary

1) A form of compensation based on a percentage of revenue or unit sales generated under an agreement, typically a patent or copyright licensing contract. 2) A compulsory payment required under statute in exchange for the right to use or sell certain property -- for example, a statutory royalty that is paid by the sellers of musical ringtones to the copyright owners of the underlying songs.

Definition provided by Nolo’s Plain-English Law Dictionary.