a pound to a penny

bet (someone) a pound to a penny

To be convinced that something is very probable or likely (to happen or be the case). Primarily heard in UK. I've been hearing about layoffs and pay cuts for a while now, but I bet you a pound to a penny that none of the executives see a drop in their salaries. I'd bet a pound to a penny this issue was caused by a computer virus someone accidentally downloaded.See also: bet, penny, pound

a pound to a penny

it is extremely likely. informalSee also: penny, pound