Tripledecker is a word that describes something that has three levels or layers. There are many synonyms that can be used to describe this concept. One option is "tri-level," which implies that something has three distinct levels. "Triple-layered" is another option, which suggests that there are three different layers that make up the whole. "Three-tiered" is similar to "tri-level" but has a more formal connotation, making it a good option for describing high-end products or architecture. "Three-story" is also a good synonym, especially when describing buildings or houses. No matter which synonym is used, it can help add variety and interest to written or spoken language.