rathole

[ rat-hohl ]
/ ˈrætˌhoʊl /

noun

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.

Idioms

    down the rathole, for a worthless purpose or purposes: seeing your inheritance disappear down the rathole.

Origin of rathole

First recorded in 1805–15; rat + hole
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for rat-hole