Green’s Dictionary of Slang

of a place, dirty, run-down, squalid.

1936		J.T. Farrell World I Never Made 190: I had my share of tank towns, dumpy hotels.
1956		‘Ed Lacy’ Men from the Boys (1967) 52: That’s why I’m living in this dumpy hotel.
1965		C. Brown Manchild in the Promised Land (1969) 264: It was enough to pay for a dumpy hotel room.
1981		J. Ellroy Brown’s Requiem 37: It was a dumpy beer bar.
2012		L. Berney Whiplash River [ebook] [T]hen go on back to their dumpy hotel room and wait to do it all over again.
2023		(con. 1962) J. Ellroy Enchanters 154: [T]his sickly woman bought the dumpiest house in all of Brentwood.