"Blood Clot" is the most virulent insult in Jamaican Patois English. It is similar to 'fuck' in usage, but does not change form for different parts of speech. Blood Clot has entered the slang lexicon in other dialects of English through the Rastafarian sub-culture.

It can be an noun, as in "Shut up, blood clot," or, more commonly, an adjective, as in "The blood clot government is cracking down on the growing of the herb."

'Clot' is the Jamaican Patois word for cloth - therefore a 'blood clot' would be a cloth used to deal with menstrual episodes.