MCHAT is when you talk complete and utter bullshit for hours on end whilst high on MCAT aka Mephedrone. This is due to the effect of MCAT which makes people extremely talkative.
by young-reezy February 05, 2010
I just finished my McHat-trick with a BigMac Meal and I think I might die! See also gluttony and fatass
by Ronald McFatass December 08, 2009