expression which literally translates to 'Going to not do that' or 'Please do not do that'.
Used in the comedy show Chewin the fat as in the sketch
'Gonnae no dae that'
'Jist, gonnae no'
Which means, 'Please don't do that' , 'Why not?' , 'Just, please, don't'.
I guess if you don't know the Glasgow accent it aint so funny, but it sure makes me laugh.