Done deal is a phrase commonly used to express that an agreement or transaction has been fully completed and is now set in stone. However, there are several other phrases that convey a similar meaning, such as a sealed deal, a closed deal, a finalized agreement, a complete transaction, or a set arrangement. These synonyms can be used interchangeably in various contexts while effectively conveying the same message. Whichever synonym one chooses to use, the phrase should connote a sense of finality and the understanding that there is no further negotiation or alteration required.