Dictionary.net

Contracts. He who, at an auction, offers the greatest price for the property sold.

The highest bidder is entitled to have the article sold at his bid, provided there has been no unfairness on his part. A distinction has been made between the highest and the best bidder. In judicial sales, where the highest bidder is unable to pay, it is said the sheriff may offer the property to the next highest, who will pay, and he is considered the highest best bidder. 1 Dall. R. 419.