What does it mean to be “Boolin'” or “Bool”?
The term and slang “Boolin'” (also spelled Booling) is a verb, which was popularized by YG. The words “Bool” and “Boolin'” are derived from Blood gang culture, which avoids the letter “C” due to rivalry with the Crips.
Bool means cool.
Boolin' means chilling or cooling.
Read: What does “Plug” mean?