Being intoxicated on three substances simultaneously.
Generally Alcohol, Marijuana, and some other substance. The third ingredient is really personal preference but some popular choices include:
A good trifecta is the nicotine, weed, alcohol which gets you in a good party mood and balancing the three types of buzz is very important.
Dude 1: I had an amazing Tri Fade going last night. I smoked two blunts, was dipping for for like an hour and then pounded 5 beers and 6 shots.
Dude 2: Sounds nice. Tobacco focuses the senses, Alcohol makes you want to party, and weed just makes it all feel so pleasant.
Dude 1: Hell yeah, I'm trying the Quad Fade next friday!