from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Slang A small or worthless amount: His advice wasn't worth diddly to me.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A small amount of no worth.
- interj. A written representation of a trill sound.
- n. penis
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a small worthless amount
Short for diddlyshit; see diddly-squat.(American Heritage® Dictionary of the English Language, Fourth Edition)
Short for diddly-squat (Wiktionary)
Imitating a sound (Wiktionary)
Possibly shortened from diddlywhacker. (Wiktionary)