1. A term used to describe an intense sexual experience that usually occurs, but isn't limited to prisons and penitentiaries. The act is so rough that the receiver of the act finds themselves pinned palms flat against a wall or floor. This can be common during surprise butt sex or other surprise sex maneuvers.

2. A phrase that describes how hard you got owned or were defeated by another person, group, entity or poltergeist.
"Why you walking like that?"
"Girl, Tevon got me palms flat last night. I won't be walking right for a week."
by Nevan April 26, 2017