Green’s Dictionary of Slang

1. to behave in a cowardly manner, to back down, to squirm.

1919		Aussie (France) X Jan. 11/1: A certain Rosella in the Aussie Army is known as Old Bloodlust, partly on account of him viewing the war as a personal quarrel between himself and the whole Hun Army, and partly on account of always regarding a soldier proceeding in a direction other than towards the Front Line as squibbing it.
1927		Barrier Miner (Broken Hill, NSW) 1/4: A lot of people think that I have squibbed it with Wetherall. I have not squibbed it and will never squib it to any man.
1932		Argus (Melbourne) 25/3: I have just ‘socked’ him in the jaw and he ‘squibbed’ it. He is just a bush rat.
1941		Baker Popular Dict. Aus. Sl. 71: Squib, to, to funk, to be afraid of something.
1942		Kalgoorlie Miner WA) 12 Dec. : That’s an other of your cheer-chasers. You weren’t game to fight for your country in the last war; squibbing it every time; just a cheer-chaser, just a squib.
1943		Mirror (Perth) 8 May 14/3: [headline] Olly Ward is No Squib [...] And just to prove he wasn’t squibbing it, Ward offers to put up £20 [...] to fight Stan Walsh.
1948		Barrier Miner (Broken Hill, NSW) 29 June 2/4: As Mattey was absent from the challenged meeting, Nick claimed that he had squibbed.
1960		J. Iggulden Storms of Summer 95: Ya reckon I ought to squib it do ya? No, Charlie. We’ll stick around.
1973		(con. 1930s) F. Huelin ‘Keep Moving’ 56: I don’t want yous to think I’m squibbin’. Whatever’s decided I’ll be in it.
1996		K. Lette Mad Cows 286: I was gunna get me ear pierced, but I squibbed it.

2. to evade a responsibility, to shirk a duty, to betray, to let down.

1949		L. Glassop Lucky Palmer 222: ‘Don’t want it now.’ ‘What, are yous squibbin ’it?’.
1955		D. Niland Shiralee 50: I’m not squibbing the issue.
1968		S. Gore Holy Smoke 56: I won’t squib it no more, over Ninevah or any other crook job.