on the rag

From rag as a slang term for a menstrual pad. First use appears c. 1967. See cite below.

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on the rag

1. (idiomatic, vulgar, slang, sometimes euphemistic) Menstruating.

   Synonym: on one's period

   • 1974, Stephen King, Carrie, page 14:

     She herself had begun menstruation shortly after her eleventh birthday and had gone to the head of the stairs to yell down excitedly: "Hey, Mum, I'm on the rag!"

   • 1983, The Big Chill:

     Harold: How is Sarah? I don't want to jump her while she's on the rag.

2. (idiomatic, derogatory, by extension) In a bad mood; angry or irritable.
   • 1967, University of South Dakota, English Dept, Current Slang, Volumes 2-5, page 5:

     On the rag, in a bad mood.—College males, Arizona. I had a lousy time last night because she was on the rag.

• Gathorne, groaneth