look up any word, like usuratonkachi:
 
1.
The act of having an illicit encounter with a hot coworker in the only private place available in the office building: the stairwell. Usually includes fluorescent lighting, strange noises from exposed pipes, and the risk of being discovered by other stairwellers. Can be very romantic despite these characteristics, depending on the parties in attendance.
"Now that we've finished discussing that project, let's move on to more pleasant topics ... I brought some supplies for our stairwelling this afternoon - wine, strawberries, and the Government Code (so our time will still be billable)."

"Sounds good. Which floor would you like to meet on?"

"How about 7, since it is a magical number, and stairwelling with you is sure to be a magical time."
by Little Miss Naughty May 27, 2005
 
2.
The act of getting caught giving a blowjob on a stairwell in a public place.
"Did you hear that Jamie and Josh were caught stairwelling by Miss Lawrence?"

"NO! EWWWWW THEY DID THAT!?!?!?! Why couldn't they have done it somewhere else! Why on the stairwell!?!?"
by DrEdition November 06, 2012