Nearly none, in slang

• Very little, in slang
• A = B = AB (anything at all)
• Nothing much, to weightlifters?
• Least amount
• Exercise that's not worth much?
• Absolutely nothing
• The least amount

WordNet Word definitions in WordNet
n. a small worthless amount; "you don't know jack" [syn: jack , diddly-squat , diddly-shit , diddlyshit , diddly , diddley , squat , shit ]

Wiktionary Word definitions in Wiktionary
n. (alternative form of diddly-squat English)