WordNet
diddly-shit
n. a small worthless amount; "you don't know jack" [syn: jack, diddly-squat, diddlysquat, diddlyshit, diddly, diddley, squat, shit]
Usage examples of "diddly-shit".
Clatterman promptly announced that he really didn't know diddly-shit about the cryptographic machine when he came aboard, and that despite Chief Schultz's on-the-job training on the voyage, he was still baffled by most of what he was supposed to do.