A vagina that a man only has sex with because he's drunk and wants to "slam" one out. Term best applies to uglier vaginas that look like a bowl of mashed potatoes due to excess intercourse.
Man, that slamburger I took home from the bar last night was pretty gross but it still hit the spot.
Pajama casual is a term used when working from home and preparing for a video conference. All business above the waist and your pajama pants down below.