People who love to party for no particular reason. The word was coined by a group of guys stationed together at Peterson Air ForceBase in Colorado Springs during 1983-1985.
1. A dirty, non-good, terrible, vile, stupid, and disgusting person. A Trash Monster has zero redeemable qualities. This is the worst insult you can use on a person.
2. A person who has wronged you in some way and so you lash out at them combining two insults into one, less insulting insult.
Me: WHY are you going to attack the innkeeper? Just have someone ask to lower the price.
My (supposed) friend: Nah I want to get a free room *hits self in balls trying to hit the inkeeper*
Me: You Trash Monster.
Someone who routinely goes looking for trash to steal. The definition of "trash" is relative; that might mean physical garbage, a whore, or just very, very dirty things.