Twin engines refer to two engines that operate in tandem to provide power to an aircraft. If you are writing about twin engines and you want to use a different word, there are plenty of options to choose from. For example, you can use the phrase "double engines," "paired engines," or "dual engines" as synonyms for twin engines. Another way to refer to twin engines is "symmetrical engines," which describes how the two engines are positioned in relation to one another. Lastly, you can also use the term "twin powerplants" to describe a pair of engines that work together to move an aircraft through the air.