The term "epactal bone" refers to a specific bone that is often found in the wrist joint. It is a small, triangular-shaped bone located in the middle of the wrist. While there are no known direct synonyms for the term "epactal bone", it is sometimes referred to as "os epactale" or "os magnum". These alternative names are not commonly used and are often specific to medical or anatomical discussions. The epactal bone plays a crucial role in the stability and mobility of the wrist joint, working in conjunction with other bones to facilitate movement and support the hand's various functions.