A term taken from the drug culture for a spontaneous act for instant gratification. Note: this was a term my wife used without knowing the original true meaning to refer to why she picked up a pecan pie at the super market. She did know the original meaning had something to do with drugs.
When I got home last night I found my girlfriend in the closet freebasing a half gallon of ice cream.
She picked up the pecan pie on the way home because she felt like freebasing.