1) To get your ass handed to you in a nice fluffy basket.
2) To otherwise get your shit ruined.
3) To be on the wrong side of a one-sided fistfight.
4) To recieve or perform manual action on yourself.
NOTE: Exists only in the perfect and future perfect forms.
1) Think I'm soft? You'll get tossed!
2) Andy got tossed when he called that biker a pussy.
3) Jack's going to the dentist today to fix his mouth after Bruce tossed him.
4) I got my salad tossed by Jack's sister when he was at the dentist.
Inflected form of TOS when applying it to another person where the subject will either flag or manipulate the victim's account (through trolling, or some other means) as-if the victim had violated the terms of service for a particular site, thus getting the victim's account flagged and/or banned.
This term originated back in the days of the early internet when the majority of the USA would use America Online as their service provider. During those times, TOSing was considered a legitimate form of "punting" a user.
That account was just trolling super hard, so I flagged his account and it ended up getting TOSsed.