duty

duty /ˈduːti/ Brit /ˈdjuːti/ noun
plural duties
duty
/ˈduːti/ Brit /ˈdjuːti/
noun
plural duties
Britannica Dictionary definition of DUTY
1 
: something that is done as part of a job
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Synonyms see: [1]task
2 
: something that you must do because it is morally right or because the law requires it
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3 
[noncount] : active military service
4 
: a tax on goods that are being brought into a country
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do duty as

1 
: to do the work of (someone or something)
2 
: to be used as (something)

off duty

: not working at a particular time

on duty

: working at a particular time