When referring to the individual in charge of a military unit, often known as a commanding officer, there are several synonyms that can be used. A general officer or flag officer are terms that describe the highest-ranking officers and are typically used in reference to those at the top of the chain of command. Other synonyms include colonel, captain, and commander, which are all commonly used to describe officers of various rank. Meanwhile, the term senior officer often refers to those in charge of a specific department or area within a military organization. The specific term used will depend on the context and rank of the individual being referred to.