What adjective describes matters pertaining to the church or clergy?

The adjective that specifically pertains to matters concerning the church or clergy is "ecclesiastic." This term is derived from the Greek word "ekklēsia," which refers to a church or assembly. It is often used to describe things that are related to the formal structure, governance, and activities of religious institutions, particularly those of the Christian church. Therefore, when discussing roles, duties, or territories associated with the clergy or the church, "ecclesiastic" is the most precise term to use.

While "spiritual" refers broadly to matters of the soul or spirit, and "religious" encompasses a wider range of beliefs and practices, "ecclesiastic" is uniquely focused on the organized church itself. Similarly, "clerical" can describe tasks typically performed by clergy or pertain to clerks or office duties within a church setting, but it does not carry the same connotation of formal church governance as "ecclesiastic" does.