LEARNit Dictionary
tour of duty
noun
/ˌtʊər əv ˈdjuːti/
UK
/ˌtʊr əv ˈduːti/
US
1
a period of time when somebody is serving in the armed forces or as a diplomat in a particular place
دوره خدمت, زمان مأموریت, دوره مأموریت