The Full Form of ACJM is‍ Additional Chief Judicial Magistrate.

The term magistrate is used in a variety of systems of governments and laws to refer to a civilian officer who administers the law. In ancient Rome, a magistratus was one of the highest ranking government officers, and possessed both judicial and executive powers. In other parts of the world, such as China, a magistrate was responsible for administration over a particular geographic area. Today, in some jurisdictions, a magistrate is a judicial officer who hears cases in a lower court, and typically deals with more minor or preliminary matters. In other jurisdictions (e.g., England and Wales), magistrates may be volunteers without formal legal training who perform a judicial role with regard to minor matters.