Actually derived from the word 'tony' but said with a pot-head accent (to-nay). After taking 3+ grav hits, or 2+ bong hits, you are considered 'tonay', or extremely high to the point of satisfaction. The word "dungay" (coming from the word dungy) can be added for extra emphasis.
"Man, after those gravs you packed me last night I was tonay." "DUH. I was tonay dungay after taking 4."