bet a dollar to a doughnut

Etymology
Possibly adapted from "bet dollars to buttons" and "bet dollars to dumplings" that appeared in the 1880s, meaning "to feel almost certain" because the dollars are bet against something nearly worthless and perhaps shaped like a zero.

Verb

 * 1)  To declare with confidence.

Usage notes

 * Becoming dated in places where the price of a doughnut now approaches or exceeds one dollar.