Tepidosity is the state of being tepid. When something is tepid, it's pretty hot/cool. whateva.
Tom : That movie was so cool!
Tim : DON"T SAY COOL! It's so uncool.
Tom : Ok. That movie was so... Hot!
Tim : Paris Hilton totally stole hot. say tepid, dude.
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?"