Green’s Dictionary of Slang

(Scot./Aus.) to escape, to decamp, to hurry away.

1885		Bulletin (Sydney) 21 Feb. 14/3: [T]here came sauntering up a tall well dressed gentleman in white gloves, with gold letters on his cap, whose presence we found so objectionable, that we, like the rest of the crowd, thought it were better to ‘nit,’ and soon the lively scene was in sole possession of our blue-coated masher.
1897		W.T. Goodge ‘Great Aus. Slanguage’ in Baker Aus. Lang. (1945) 116: And to nark it means to stop it, / And to nit it means to fly!
1901		Truth (Sydney) 29 Sept. 7/3: Wot they pulls, so he can wing / When as how he gets the offis / For to nit if things is high.
1935		(con. 1920s) McArthur & Long No Mean City 11: ‘Nit the jorrie (Leave the girl alone)!’ he yelled. ‘Nark it! nark it!’.
1941		Baker Popular Dict. Aus. Sl. 49: To nit, to decamp, get away (from a foe).