n.1. a. A period of seven days: a week of rain.
b. A seven-day calendar period, especially one starting with Sunday and continuing through Saturday: this week.
2. a. A week designated by an event or holiday occurring within it: commencement week.
b. A week dedicated to a particular cause or institution: Home Safety Week.
3. The part of a calendar week devoted to work, school, or business: working a three-day week.
4. a. One week from a specified day: I'll see you Friday week.
b. One week ago from a specified day: It was Friday week that we last met.