perquisite

Concise Oxford English Dictionary © 2008 Oxford University Press:
perquisite /ˈpəːkwɪzɪt/

▶noun

• 1 formal a special right or privilege enjoyed as a result of one's position.

• 2 historical a thing which has served its primary use and to which a subordinate or employee has a customary right.

– origin ME: from med. L. perquisitum ‘acquisition’, from L. perquirere ‘search diligently for’.