Uckers is a slang term for a woman who is particularly gifted at, or frequently performs, fellatio.
Uckers broke into popular media in the 2015 song “4 Door Coming” by British rappers, 410. 410 is a British gang based out of Brixton, London and central to a genre of music known as UK Drill. In the song, one person raps: “Tell a bitch keep her face down / Who ever told you we’re lovers? / Three balls on her tongue / Uckers, badders.”
Uck is Multicultural London English slang for oral sex (likely from suck or fuck or an imitation of the sound) and badders is London slang for a person who is sexually experienced. Uckers badders, then, is a woman practiced at the BJ.
“4 Door Coming” helped popularize the term among hip-hop fans and youth more generally. After its release, uckers and uckers badders caught on as slang for a fellatio or a woman who performs it on a man.
Performer Michael Dapaah, playing his comic rap character “Big Shaq,” further spread uckers in his a viral 2017 “Man’s Not Hot,” a satire of UK drill with nonsensical lyrics including math problems, gun sounds, the alphabet, and the line “that girl is a uckers.”