Bumbaclot is a common Jamaican slang term used to insult people.
If you call someone a Bumbaclot, you are basically calling them an asswipe, or even a menstrual pad.
You are basically calling them the cloth you use to wipe your nether regions.
It is expressed if you are annoyed or disgusted by someone, and you want them to know it.
As it comes from Jamaica, it is known as a Rasta curse word, as even the peaceful Rastafaris need a word to show dismay.
Bumbaclot is a version of the Jamaican English word bomboclaat.
Bombo or bumba is a West African word that means something along the lines of the female sex organ or butt/bum. Clot or claat means cloth.
The term was originally mainly used about the cloths women would wipe menstruation blood with, before sanitary products such as tampons and pads became a thing.
The term is commonly used by Jamaicans, but has been adopted by white people, particularly Americans.
However, POC have started making fun of white people who use the word without knowing its actual meaning, and therefore end up using it in unfitting situations.