一週[isshuu] one week
一週間[isshuukan] one week
今週[konshuu] this week
今週中に[konshuujuuni] before the week is out
さ来週[saraishuu] week after next

七週の祭[nanamawarinoiwai] the Feast of Weeks
七週の祭り[nanashuunomatsuri] the Feast of Weeks
週刊[shuukan] published weekly
週刊雑誌[shuukanzasshi] weekly magazine

週齡[shuurei] week-old