duty

noun

1. 1

   That which one is morally or legally obligated to do.

   “We don't have a duty to keep you here.”

2. 2

   The state of being at work and responsible for or doing a particular task.

   “I’m on duty from 6 pm to 6 am.”

3. 3

   A tax placed on imports or exports; a tariff.

4. 4

   One's due, something one is owed; a debt or fee.

5. 5

   Respect; reverence; regard; act of respect; homage.

6. 6

   The efficiency of an engine, especially a steam pumping engine, as measured by work done by a certain quantity of fuel; usually, the number of pounds of water lifted one foot by one bushel of coal (94 lbs. old standard), or by 1 cwt. (112 lbs., England, or 100 lbs., United States).