perquisite \PUR-kwuh-zit\ (noun) - 1 : A profit or benefit in addition to a salary or wages. 2 : Broadly: The benefits of a position or office. 3 : A gratuity or tip for services performed. 4 : Anything to which someone has or claims the sole right.
"Yourself you've fixed the ransom of this couple at twenty thousand pieces, and, as I gather, the lady is to be your perquisite. But why should she be your perquisite more than another's, seeing that she belongs by the articles to all of us, as a prize of war?" -- Rafael Sabatini, 'Captain Blood'
Perquisite derives from Medieval Latin perquisitum, from the past participle of Latin perquirere, "to search for eagerly," from per-, "through, thoroughly" + quaerere, "to seek." In Middle English it meant "property acquired by means other than inheritance." By 1565 it had acquired the sense "fringe benefit"; by 1721 it had also come to signify "a tip or gratuity."