1. slang A useless drunkard. Sometimes hyphenated. This part of town is filled with addicts and rumdums. That old rum-dum hasn't held down a job in over 10 years. He's been too busy roaming from bar to bar.
2. slang A very stupid, bumbling, incompetent person. Sometimes hyphenated. I can't believe they appointed that rumdum to run the company. This device is so simple that even rum-dum like me can use it.
Farlex Dictionary of Idioms. © 2022 Farlex, Inc, all rights reserved.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.