It's crude. A 'dick move' would be an action that is stupid, mean and/or unethical in some way. The term originates from the person behaving like a dick (an idiot or generally contemptible person.) 'Dick' is another word for 'penis', hence why I said it is crude. Peter's advice seems pretty sound, I would not suggest you use it unless you have a high level of English.

Hard to say if there is no context - sounds like American slang so you would not want to use or repeat it unless you are fluent in American English.