When you feel like dancing (boogeying), but you still feel really chill and laid back. So chill and elastic that you feel like a rubber-band in the groove and can move every part of your body. Can also describe laid back head nodding music.
This can also describe when you are in the zone, a really good mood, or just feelin' really good.
The Roots were so boogachillastic tonight. I felt like dancing, but could also just lay back, relax, and nod my head.
Got a great nights rest, just got paid, have the day off tomorrow, and about to go kick it with some friends. I feel so boogachillastic.