verb: (US colloquial, transitive) To cause a group of people to lie in a pile upon another, originally as a punishment to the victim on the bottom.
verb: (US colloquial, transitive, intransitive) To jump into such a pile.
verb: (figuratively, US colloquial, transitive, intransitive) To act similarly with regard to residential density: to live or cause to live in high-density settlements.
noun: (US, colloquial) A disorderly pile of people formed by jumping upon a victim.
