To be illustrious, this means you are one of the town. You are a well known being in said area because an old folktale speculated that Illustrious people pooprainbow coloured gold.
She's so illustrious, I once saw her behind the bushes in Tonbridge dumping one out. It was rainbow.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"