rag week

Today it means: An annual event in many universities where students engage in unusual activities to raise money for charity. Full definition →

rag week · noun¹

From rag (“university students society run for charitable fundraising”) + week, possibly from the verb rag (“tease; torment; banter”).

From rag (“piece of old cloth”) + week. From the former use, by women, of rags to protect their clothing from menstrual blood.

Etymology from Wiktionary, CC BY-SA 4.0.