1a moral or legal obligation; a responsibility:it’s my duty to uphold the lawshe was determined to do her duty as a citizen [mass noun]:a strong sense of duty
[as modifier] (of a visit or other undertaking) done from a sense of moral obligation rather than for pleasure:a fifteen-minute duty visit
2 (often duties) a task or action that one is required to perform as part of one’s job:the queen’s official dutiesyour duties will include operating the switchboard [mass noun]:Juliet reported for duty
[mass noun] military service:combat duty in the army
[as modifier] (of a person) engaged in their regular work:a duty nurse
[mass noun] (also duties) performance of prescribed church services by a priest or minister:he was willing to take Sunday duties
3a payment levied on the import, export, manufacture, or sale of goods:a 6 per cent duty on imports [mass noun]:goods subject to excise duty
British a payment levied on the transfer of property, for licences, and for the legal recognition of documents.
4 technical the measure of an engine’s effectiveness in units of work done per unit of fuel.
do duty as (or for)
serve or act as a substitute for something else:the rusting shack which did duty as the bridge
on (or off) duty
engaged (or not engaged) in one’s regular work:the doorman had gone off duty and the lobby was unattended
