nah a typically turkish cultural gesture which expresses misbelieve, distrust, challenge, opposition or disobedience. nah occurs when someone puts his/her thumb between forefinger and middle finger and the nahhed fist is shown to the person at whom it is aimed.
a more brutal version of the gesture exists, by creating a "slash" like sound after turning the nahhed fist with an immediate forward motion, in order that the nahhed wrist hits the other hand's palm.
literally nah means "like the hell it is?"
-Person 1 : Can you lend me your car?
-Person 2 : Nah!