Hmm, well I googled 'etymology of git' and went to Wikipedia, an extract:
"Etymology 1
From Middle English get (“offspring", especially "illegitimate offspring”). A southern variant of Scots get (“illegitimate child, brat”), related to beget. (from Online Etymology Dictionary)
Noun
git (plural gits)
1.(UK, slang, pejorative) A contemptible person.
2.(UK, slang, pejorative) A silly, incompetent, stupid, annoying or childish person. ?[quotations ?]
Usage notes 'Git' is usually used as an insult, more severe than twit but less severe than a true profanity like
wanker or
arsehole, and may often be used affectionately between friends. 'Get' can also be used, with a subtle change of meaning. 'You cheeky get!' is slightly less harsh than 'You cheeky git!'.
'Git' is frequently used in conjunction with another word to achieve a more specific meaning. For instance a "smarmy git" refers to a person of a slimy, ingratiating disposition; a "jammy git" would be a person with undeserved luck.
The phrase "grumpy old git", denoting a cantankerous old man, is used with particular frequency. In parts of northern England, Northern Ireland and Scotland, 'get' is still used in preference to 'git'.
The word has been ruled by the Speaker of the House of Commons to be unparliamentary language(I really like that last bit!)
I must admit, I use the word 'get' as in
'spawny get' (ie: incredibly lucky bastard) more than 'git' - didn't realise it was a scottish word in origin
I've also always thought it more like the bit I've coloured in blue, not so much the 'contemptible' bit, or 'stupid' connotation...
Ah well, learn something new everyday, eh?!