duty Look up duty at Dictionary.com
c.1300, from Anglo-Fr. duete, from O.Fr. deu "due, owed," from V.L. *debutus, from L. debitus, pp. of debere "to owe." Related: Duties. The sense of "tax or fee in imports, exports, etc." is from late 15c.; duty-free as a noun is attested from 1958.