This term is a derivative of the words blackout and well. It is the act of becoming so drunk that you do not remember what you did the next day. Your head feels as though you fell in a well. Getting blackwelled usually means you had fun the night before.
Jim: Man, my head hurts so much... What happened last night?
Matt: You got blackwelled man. It happens to the best of us.
Jim: I got so blackwelled last night. I woke up in a room full of people I didnt' know!
Matt: Sounds like you had a good time man.
Matt: You got blackwelled man. It happens to the best of us.
Jim: I got so blackwelled last night. I woke up in a room full of people I didnt' know!
Matt: Sounds like you had a good time man.
by tyty133 July 09, 2013