noun pl. duties -·ties

1. the obedience or respect that one should show toward one's parents, older people, etc.
2. conduct based on moral or legal obligation, or a sense of propriety one's duty to vote
3. any action, task, etc. required by or relating to one's occupation or position the duties of a secretary
4. a sense or feeling of obligation duty calls
5. service, esp. military service overseas duty
6. a payment due to the government, esp. a tax imposed on imports, exports, or manufactured goods
7. Brit. the performance of a machine as measured by the output of work per unit of fuel
8. the amount of work that a machine is meant to do; rated efficiency under specified conditions
9. ☆ Agric. the amount of water needed for irrigation per acre per crop
   also duty of water

Etymology: ME duete < Anglo-Fr dueté, what is due (owing): see due & -ty