In golf, a hole-in-one with no witnesses except the player. By extension, any unusual, rare, wonderful, unlikely event, achievement, experience, etc...with only one eyewitness.
Man #1 - "I swear to God I'm telling you the absolute truth!"
Man#2 - "But you're the only witness, so it's a ghost ace, no real proof."
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.
We have a Zoom meeting in a few minutes and I’ll probably go pajama casual.