n. pl. du·ties 1. a. An act or a course of action that is required of one by position, social custom, law, or religion: the duties of being a critical care nurse.
b. Required action or service:
jury duty; beyond the call of duty. See Synonyms at
function.
c. Active military service: a tour of duty.
2. a. Moral or legal obligation: It is your duty to tell the truth.
b. The compulsion felt to meet such obligation: acting out of duty.
3. A tax charged by a government, especially on imports.
4. a. The application of something for a purpose; use: The dining room table also does duty as a desk.
b. A measure of efficiency expressed as the amount of work done per unit of energy used.
5. The total volume of water required to irrigate a given area in order to cultivate a specific crop until harvest.