A combination of shit and oh snap. For the times when you start to say shit but you realize that your grandma is in the room.
"Oh shinaps! I forgot that I am suppose to be meeting Bill right now. I'll be back in an hour, Grandma."
Your so drunk your past being hammered. Also refers to being point in your drunkeness when you are most likely to get into shenanigans you won't remember in the mourning.
Catty was so slammered last night that she thought it would be funny to break into her ex-boyfriends house.