Liquor that is particularly unpleasant or low quality. I'll never understand how you can drink that monkey swill—it's going to rot your gut! I quite like good whiskey, but not monkey swill like that.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
n. inferior liquor; strong liquor. Where did you get this monkey swill? This would kill a monkey anyway.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.