When one or a group has the need to celebrate an event or accomplishment but has recently celebrated in the form of alcohol consumption and finds it necessary to have a relaxed celebration, ie "chill".
chilling or relaxing but in an exciting and social setting or manner. (Versus just regular "chilling" when you are busy or tired... a Chillabration or Chillation is chilling with friends and having a good time. You just happened to be radiating happiness about you while you do it!)