Short for Jennifer Grey's Old Nose. Refers to the pre rhinoplasty nose of actress Jennifer Grey. Can refer to a nose of similar size or appealing feature on a person, or be used even more broadly to describe the loss of a nostalgic feature on an actor, actress, or anyone with a distinguishing physical characteristic that has since diminished through time or physical attrition.
"I'm sorry to hear she's aged so poorly, looks like she's gone the way of JGON."
"Did you hear about her latest latest implant surgery? Total JGON job!"