Green’s Dictionary of Slang

a euph. for a menstrual period.

1930		(con. 1900s–10s) Dos Passos 42nd Parallel in USA (1966) 147: She was afraid her period was coming on. She’d only had the curse a few times yet.
1942		in G. Legman Limerick (1953) 66: A person / Who was not averse / Though she had the curse.
1959		M. Richler Apprenticeship of Duddy Kravitz (1964) 199: Jeez. Have you got the curse again?
1962		F. Norman Guntz 72: One day she got the curse.
1971		M. Novotny Kings Road 98: I was terrified of getting pregnant [...] but the curse has just come on.
1981		A.K. Shulman On the Stroll 88: Starting when, Prince? I’m getting the curse.
1997		D. Farson Never a Normal Man 57: My mother explained delicately that Mopsy had the ‘curse’.
2006		‘Menses and Sexuality’ at www.enotalone.com 🌐 Semi-modern terminology such as ‘on the Rag’ or ‘She’s got the curse’ show societies ignorance and repugnant attitude toward the bleeding woman.
2017		T. Spicer Good Girl Stripped Bare 26: The menarche, a visit from Aunt Flo, on the rag, the curse, call it what you will.