Definition of "week"

week

/wik/

noun
plural weeks
1. Any period of seven consecutive days.
  Quotations
  Investors face a quandary. Cash offers a return of virtually zero in many developed countries; government-bond yields may have risen in recent weeks but they are still unattractive. Equities have suffered two big bear markets since 2000 and are wobbling again. It is hardly surprising that pension funds, insurers and endowments are searching for new sources of return.
  2013 July 6, “The rise of smart beta”, in The Economist, volume 408, number 8843, page 68
2. A period of seven days beginning with Sunday or Monday.
3. A period of five days beginning with Monday.
4. A subdivision of the month into longer periods of work days punctuated by shorter weekend periods of days for markets, rest, or religious observation such as a sabbath.
adjective
not comparable
1. (postpositive) Seven days after (sometimes before) a specified date.