Corner Case

A use case, situation or artifact of a project that you and/or your colleges completely missed. It's a nice way of wording the fact that someone overlooked something important and now suddenly it's apparent to everyone.

Guy 1: Oh shit the freakin program is crashing immediately. I think the problem is the database isn't installed!

Guy 2: Yeah... another corner case. Good thing we're checkin' all the angles. Maybe we should put some hand rails around this one.