To estimate the level of fat in a person, animal, or other object that might contain lard, lumpish, or tubby properties.
$1750 divided by $5? That means you're like... 800 pounds! (Or something like that. I'm too lazy to do maths right now). I guess for now I can just fatstimate it.
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?"