* "Mean" can be used as a synonym for "bad" or "nasty" - This is often used in conjunction with other Cockney slang words. For example, "He's a right meanie" could mean "He's a really bad person."
* "Mean" can also refer to something "bad" or "undesirable" in a more general sense - For example, "That was a mean trick" would mean "That was a bad thing to do."
Remember that Cockney slang is constantly evolving, and the meaning of words can change over time. If you are unsure of the meaning of a word, it is always best to ask a native speaker or consult a dictionary of Cockney slang.