to assist a climber by pushing him/her upwards
"'ere Stephen, g'is a bunk up, I'm nearly over this wall."
by theWestHamfan October 27, 2003
I had a lovely bunk up with Britney last night.
by Dunky Oggins October 17, 2003
The process of copulation/fornication.
You couldn't get a bunk up in Bangkok mate!
by Robbo_69 May 20, 2008