To have a festival, celebrate, and/or party with great zeal and to an almost superfluous extent.
The word combines both festival and celebrate in order to describe a formerly unknown level of revelry. Instead of the normal levels of celebration, partying and festivities, this transcends popular convention to ascertain a deity-like level of merriment.
An occasion in which this occurs is known as a festivation.
1. Dude, my bro Josh is coming back from being in Afghanistan for, like, a year. We're throwing a huge festivation for him.
2. Yo, it's been a shitty week. I'm gonna hit the clubs and festivate so hard in there, I'll get kicked off the strip for life!
To get festive, to get in the Holiday Spirit.
"I'm tired of all of you pooh-poohing the office Holiday Party. They'll have free booze and food! C'mon, it's time to festivate!"