Green’s Dictionary of Slang

nah-uh! excl.

(US teen/black) an emphatic excl. of denial, refusal, the antonym of SE uh-huh!

[US]Teen Lingo: The Source for Youth Ministry [Internet] nah-uh! 1. An exclamation proclaiming resistance. ‘Pick up garbage? Nah-uh! Not me!’.