Grass Whistle 

An offensive manuever done by bending over and placing your head between your legs. Then take your middle finger and put it right in front of your ass, and fart. Your finger will resemble a blade of grass as it blows through the wind.

He really must have been pissed, because he totally gave that guy the grass whistle.

Grass Whistle by th3_duk3 September 8, 2009

Grass Wistle

An offensive gesture performed by bending over and placing your head between your legs. Then take your middle finger and place it in front of your ass and fart. Your finger will resemble a blade of grass as it blows through the wind.

Some jerk gave me the Grass Wistle after I yelled at him for cutting in line at Burger King.

Grass Wistle by DaBigDuk3 September 8, 2009

Grasswhistle 

a term used used for when a vegan moans while getting head.

i heard them damn vegans blowing the grasswhistle

Grasswhistle by bootyisvegan May 6, 2023