workweek vs week

workweek and week both are nouns.

Word	Noun	Adjective	Verb	Adverb
workweek	Yes	No	No	No
week	Yes	No	No	No

As nouns, workweek and week are synonyms defined as:

workweek (noun)	week (noun)
hours or days of work in a calendar week	any period of seven consecutive days
	hours or days of work in a calendar week
	a period of seven consecutive days (usually reckoned to be from Sunday to Saturday, or from Monday to Sunday)