Every week, weekly. / From one week to the next.

(UK, Canada) A week during a university's term where no teaching takes place, generally so that students may prepare for tests. / (Canada) A spring break; often specifically the March break.

(marketing) A week that is in high demand because it is in a holiday high season. Especially used in time-share, but not limited to this industry.

(marketing) A week that is in low demand because it is in a holiday low season. Especially used in time-share, but not limited to this industry.

plural of week-end

Any of several extended holidays celebrated in China and Japan, usually early in May.

(business, marketing) The period after Christmas (December 25th) until New Year's (or longer), when stores offer large discounts

(chiefly US, idiomatic) The week during which new members are required to undergo undignified rites of initiation or gruelling discipline in order to be accepted into a fraternity, sorority, secret society, military group, etc.

plural of dead week

(Christianity) The week beginning on Passion Sunday.