do duty for something Definition

duty
noun duties

1. Something one is or feels obliged to do; a moral or legal responsibility, or the awareness of it.

Thesaurus: obligation, calling, service, mission.
2. A task to be performed, especially in connection with a job.

Thesaurus: office, task, function, service, chore.
3. Tax on goods, especially imports.

Thesaurus: tax, charge, tariff, toll, revenue, custom, levy, excise.
4. Respect for elders, seniors or superiors.

Derivative: dutiful
adj

Fulfilling or aware of one's duty
Thesaurus: respectful, obedient, acquiescent, deferential, devoted, submissive, docile, compliant, complaisant, filial; Antonym: fractious.

Derivative: dutifully
adverb

Idiom: do duty for something

To serve in its place; to act as a substitute for it.

Idiom: on duty

Working; liable to be called upon to go into action.

Idiom: off duty

Not on duty.

Etymology: 13c: from French dueté.