When you call another person a `git’, what you mean is that you dislike him because you find him annoying. The `g’ is like the `g’ in `get’ and `guess’, and the following `it’ is pronounced like the word `it’. `Git’ is used in British English in informal contexts to refer to a man.
Examples: *How could you have fallen in love with a git like him? *Tell the git standing over there to stop whistling.
The word is also used to mean `get’.