The celebatory date that you got a much anticipated severence package from a job you hated or were planningto leave anyway.
"I thought I'd pick up some champagne and a cigar to celebrate my Caniversary - one year ago today!" said Terry.
"Screw You- I still can't believe you got 18 months salary to leave that piece of crap job especially when you were going to quit anyway!" said Larry.
The yearly celebration of a person's first time trying or enjoying cannabis in some form. Sometimes celebrated by sharing one's cannabis or paraphernalia with members of their smoking community (reddit.com/trees, for example). Can also be celebrated with cannabis-infused space cake with candles.
Also, just another reason to get together with your stoner friends and get baked. Not to be confused with 4/20, the annual holiday that celebrates pot culture in general.
Miles invites his stoner circle over to his house every year at 4:20 on July 5th to celebrate his canniversary with them. They usually bring him gifts of rolling papers, a dub sack, and next year, they're going to Amsterdam for his canniversary!