In reply to TamMor:
I had a stay in a US lab once where the chief technician was a fan of UK vernacular. She wanted to know how phrases were used. The example of 'git' or 'get <northern>' came up. I explained that calling someone a git in a light-hearted way was fine (most of the time), a 'bit of a git' meant they were rather unsavoury and 'a complete and utter git' meant you were serious. As I left I wanted to get her a present, so found a suitable book (not Profanisaurus before you ask). I wanted to check that it was accurate - so I looked up 'git'
Git or get - unpleasant person
Usage: 'Who's the git in the orange trousers?'
Told me it was accurate!