Definitions by Gus Grant

NANANAI 

Supreme expressionism. Can often be said randomly or when excited.

Expression of happiness or joy best when slurred in a deep voice.

Also famously used in a song by N-Dubz.

Mainly used in the depths of SW London.

Boy1: we got no chemistry test.
Boy2: yeahhhh NANANAI or NANANAAAIIIIIIIIIII (slurred - deep voice)

NANANAI by Gus Grant February 23, 2008