An ecclesiastic attached to the chapel of a military unit is known as a?

A chaplain is specifically designated to provide spiritual support and guidance to military personnel. This role involves offering services, conducting religious ceremonies, and providing emotional support to members of the military and their families, regardless of their specific religious affiliation. Chaplains play a crucial role in fostering a sense of community and addressing the spiritual needs of individuals in a military environment.

In contrast, a commander refers to a military officer in charge of a unit, responsible for strategic decision-making and leadership. A bishop is a senior member of the Christian clergy, often overseeing multiple parishes, but not necessarily linked directly to military units. The title "Sgt. at Arms" typically refers to a position responsible for maintaining order during meetings and enforcing rules, which is unrelated to spiritual services within a military context. Thus, the role of a chaplain uniquely fits the description provided in the question.