Wiktionary
sealed bid
n. A cost estimate, or a proposal to buy something, the value of which is kept secret from competitors until all such bids have been made.
Usage examples of "sealed bid".
At that time, I will ask that you each give me a sealed bid for the property.
He wasn't sure what he was going to request when he finally submitted his sealed bid to Glory, but he knew it would be something much better than just asking God to burn Jase McClellan in the fiery pit until his eyeballs melted and his hair frizzled away and the skin on his face blackened and cracked and flaked from the charting bones and his dick fell off.