Senior House

A house with a large number of bedrooms (usually 9-14) on a college campus made up of mostly seniors that are in the same fraternity. It is used as a place to hold parties since many fraternities are supposed to be dry (alcohol-free). It is different from a fraternity house in that it doesn't have a dance floor, a large living room, is not old and made of brick/stone, and it has way less bedrooms.

Joe: dude , are there any parties tonight?
Matt: yeah man at XXX (fraternity).
Joe: oh nice, at the fraternity house?
Matt: No, at the senior house.