perquisite (n.)
mid-15c., "property acquired other than by inheritance," from Medieval Latin perquisitum "thing gained, profit," in classical Latin, "thing sought after," noun use of neuter past participle of perquirere "to seek, ask for," from per- "thoroughly" (see per) + quærere "to seek" (see query (v.)). For Latin vowel change, see acquisition. General meaning "fee or profit on top of regular wages" first recorded 1560s.