The act of homicide in which a person, usually a child, forcefully throws a snowball on to an oncoming car that results in a death.
Billy: I just got out of the slammer.
Phillip: What did you get arrested for?
Billy: Snowhicular manslaughter; I packed the meanest snowball and absolutely destroyed a car. I got locked up for 3 years. Who ever thought a 12 year old would go to jail?