There are several synonyms for the word "sit-down." One common synonym is "seated." For example, instead of saying "I had a sit-down meeting with my boss," one could say "I had a seated meeting with my boss." Another synonym is "settled," which suggests a more relaxed or calm state of sitting. For instance, "I settled into the couch for a sit-down with my favorite book." The phrase "taking a load off" or "taking a seat" could also be used to replace "sit-down" in informal situations. Overall, there are many synonyms for "sit-down" that can add variety and nuance to your language.