Synonyms for Tour (same or very similar meaning)
WordNet sense 1 (a period of time spent in military service):
enlistment, hitch, duty tour, term of enlistment, tour of duty
WordNet sense 2 (a time for working (after which you will be relieved by someone else)):
go, spell, turn
WordNet sense 3 (a journey or route all the way around a particular place or area):
circuit
From the ODE community, based on WordNet
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