bet bottom dollar

bet (one's) bottom dollar

To be totally certain that something will happen or prove true (so much so that one would hypothetically risk one's last dollar betting on it). I lost my umbrella, so you can bet your bottom dollar on it raining tomorrow! I bet my bottom dollar that Kevin will be late tonight—he's never on time!

See also: bet, bottom, dollar

Farlex Dictionary of Idioms. © 2022 Farlex, Inc, all rights reserved.

bet one's bottom dollar

 and bet one's life

Fig. to be quite certain (about something). (A bottom dollar is the last dollar.) I'll be there. You bet your bottom dollar. I bet my bottom dollar you can't swim across the pool. You bet your life I can't swim that far.

See also: bet, bottom, dollar

McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.