doodly-squat vs diddly-shit

doodly-squat and diddly-shit both are nouns.

Word	Noun	Adjective	Verb	Adverb
doodly-squat	Yes	No	No	No
diddly-shit	Yes	No	No	No

As nouns, doodly-squat and diddly-shit are synonyms defined as:

Other synonyms of doodly-squat include diddley, diddly-squat, diddly, diddlyshit, diddlysquat, jack, shit, squat.

doodly-squat (noun)	diddly-shit (noun)
a small worthless amount	a small worthless amount