Fish Pie Sue
A contact in your phone that you have no memory about. Maybe some one you met on a night out and had a memorable feature about them that (at the time) you thought would trigger your memory the following morning.
John: "Hey who's this contact in your phone "Sexy Sally from the bar"
Chris: "Oh that's a Fish Pie Sue I have no idea who it is."
Chris: "Oh that's a Fish Pie Sue I have no idea who it is."