1. (verb) See overtoning
2. (noun) From the words overt & ringtone. The assignment of a ringtone to imply something about a caller. Usually used as a a friendly jab or an insult. For instance, overtoning Sir Mix-a-lot's "Baby Got Back" as the ringtone for a chubby friend is an overtone.
2.
Alice: Bob, who was that who just called you?
Bob: Chuck.
Alice: OMG! That's why your phone played "Macho Man!" Nice overtone.
Bob: Yeah, Chuck's totally closeted.
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?"