Green’s Dictionary of Slang

1. (orig. US) worthless rubbish, trash.

1966		(con. 1958) R. Farina Been Down So Long (1972) 64: ‘What the hell are all those things, Paps?’ ‘A whole lot of doodley-shit.’.
1971		L. Cameron First Blood 13: Any time you say doodley shit ... I’ll whip your ass.

2. nothing, anything.

1976		Jenkins & Shrake Limo 119: But it’s come to where none of this stuff means a doodly shit.
1984		W. Diehl Hooligans (2003) 63: We couldn’t prove doodly-shit.
1991		C. Gentry J. Edgar Hoover 281: Still, he managed to offend a female reporter by telling her that her opinions of Russia were ‘not worth doodleyshit.’.