Synonyms for Duty:

n.

custom, revenue. imperative, need, must. stint. application, utilization, used, use. impost, money, assessment, politics, pay. act (noun)
obligation, responsibility.
at liberty (noun)
free, at leisure, inactive, not engaged, unemployed, off, off work.
duty (noun)
liability, obligation, business, station, responsibility.
moral obligation (noun)
deference, faithfulness, obedience, accountability, reverence, integrity, respect, honesty, pledge, conscience, liability.
moral sense (noun)
conscience.
obedience (noun)
docility, subservience, submissiveness.
obligation (noun)
obligation.
off duty (noun)
free, off work, off, inactive.
price (noun)
dearness, rate, damage, cost, figure, expense, levy, tab, amount, tax, tariff, premium, quotation, price, toll, worth, charge, outlay, value.
responsibility, assignment (noun)
commitment, must, part, trust, need, task, station, engagement, contract, trouble, commission, charge, burden, undertaking, onus, office, chore, function, obligation, service, mission, business.
servility (noun)
obedience, Lowliness, servitude, yieldingness, acquiescence, fealty, inferiority, subjection, subordination, vassalage, serfdom, subservience, docility, humbleness, homage, servility, humility, willingness, submissiveness, genuflection, deference, devotion, complaisance, slavishness.
tax on foreign goods (noun)
impost, assessment, custom, tariff, revenue, customs, levy, rate, toll.
trust (noun)
guardianship.
worship (noun)
devoutness, worship, respect, Ardency, veneration, awe, deification, admiration, exaltation, adoration, idolization, faithfulness, religion, cultism, prayer, reverence, piety.

Other synonyms:

compulsion, commitment, engagement, impost, onus, guardianship. assignment, utilization, must, burden. assessment, stint, imperative, commission. need. application. assignment
task.
military service
service.
moral sense
conscience.
responsibility
trust.
task
chore.

Usage examples for duty

  1. A Villeroy could not die better than doing his duty – At Agincourt by G. A. Henty
  2. " Your first duty is to get well. – Man and Maid by Elinor Glyn
  3. Then I must do my duty – Allan and the Holy Flower by H. Rider Haggard