Green’s Dictionary of Slang

greazy adj.

1. (UK black) badly and/or poorly dressed.

[UK]G. Krauze What They Was 10: But forreal it makes sense not to look greazy when you’re the driver since you don’t wanna [...] look like you can’t afford the whip.

2. (UK black) serious, intense.

[UK]G. Krauze What They Was 137: HMP Feltham. Gang city and gladiator games. Everyone knows Feltham is greazy.