The phrase "deep-six" generally means to dispose of something, especially in a secretive or hidden manner. There are several antonyms for this phrase, which can be used to convey the opposite of deep-sixing. One such antonym is "retain," which means to keep or preserve something. Another antonym is "display," which means to present something for public view. Additionally, "exhibit" can also convey the opposite of deep-sixing, as it means to show or display something in a public space. These antonyms can be used to indicate the opposite of getting rid of something, instead focusing on keeping, showcasing, or preserving it.