perquisite

noun

1. something additional to regular profit or pay, resulting from one's position or employment, esp. something customary or expected
2. a tip or gratuity
3. a privilege or benefit to which a person, institution, etc. is entitled by virtue of status, position, or the like; prerogative; right

Etymology: ME perquysite < ML perquisitum, something acquired < neut. pp. of perquirere, to obtain, purchase < L, to search diligently for < per-, intens. + quaerere, to seek: see query