Wiktionary
silent auction
n. An auction where people bid on a piece of paper, and whoever has the highest bid wins the item.
Usage examples of "silent auction".
In a silent auction, I would either attend, or participate by 'link.
The Cretaceous Ball was our big fund-raiser, a hundred thousand dollars a seat, and in addition to the silent auction before the meal and the dancing afterwards, everybody who bought an entire table for six was entitled to their very own paleontologist as a kind of party favor.