tour vs work shift

tour and work shift both are nouns.

Word	Noun	Adjective	Verb	Adverb
tour	Yes	No	Yes	No
work shift	Yes	No	No	No

As nouns, work shift is a hypernym of tour; that is, work shift is a word with a broader meaning than tour:

tour: a time period for working (after which you will be relieved by someone else)
work shift: the time period during which you are at work

Other hypernyms of tour include duty period, shift.

tour (noun)	work shift (noun)
a journey or route all the way around a particular place or area	the time period during which you are at work
a time period for working (after which you will be relieved by someone else)
a period of time spent in military service

tour (verb)	work shift (verb)
make a tour of a certain place