Alternative spelling of blood clot, a Jamaican Patois vulgarity referring to the cloth that catches menstrual blood.
Barry Chevannes, ed., Rastafari and Other African-Caribbean Worldviews (1997), page 119:
Although the most common expletive in Jamaica, raas, refers to the anus, the most offensive is the one referring to the menses, blood klaat.
Steeve O Buckridge, Language of Dress: Resistance and Accommodation in Jamaica, 1750-1890 (2004), page 8:
Why is it that the term blood klaat (blood cloth), once used in association with women's menstrual flow, has become part of Jamaican "cuss" vocabulary and an abusive, profane term used predominantly by Jamaican men?