Is it ensure, insure, or assure?
also rathole, 1812 in figurative sense of "nasty, messy place;" rat (n.) + hole (n.). As "bottomless hole" (especially one where money goes) from 1961.
A wretched, messy place; a filthy hovel; dump: Those days we lived in a rathole (1812+)
To store up food and supplies; stockpile; stash (1950s+)
pour money down the drain