- a hole made by a rat, as into a room, barn, etc.: The first chore in the old building is to plug up the ratholes.
- the burrow or shelter of a rat.
- any small and uncomfortable room, office, apartment, etc., especially one that is dirty or disordered: He lives in a rathole near the docks.
- down the rathole, for a worthless purpose or purposes: seeing your inheritance disappear down the rathole.