Indicis is a medical term that refers to one of the muscles in the hand. Synonyms for this muscle include the first dorsal interosseous muscle, the first interosseous muscle, and the first palmar interosseous muscle. This muscle is responsible for abduction, or the movement of the fingers away from the middle finger, as well as aiding in flexion and extension. Understanding the synonyms for this muscle can be helpful for medical professionals when discussing the anatomy and function of the hand. It can also be useful for patients who may want to better understand their diagnosis or treatment options.