magisterial

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Of, relating to, or characteristic of a master or teacher; authoritative: a magisterial account of the history of the English language.
2. adj. Sedately dignified in appearance or manner: "She would appear on the porch and reign over the street in magisterial beauty” ( Harper Lee).
3. adj. Dogmatic; overbearing: expounded on official protocol in magisterial tones.
4. adj. Of or relating to a magistrate or a magistrate's official functions.

Century Dictionary and Cyclopedia

1. Of or pertaining to a master; such as befits a master; authoritative; hence, lofty; arrogant; imperious; domineering.
2. Of or belonging to a magistrate or his office; of the rank of a magistrate.
3. In chem., pertaining to magistery.
4. Synonyms Authoritative, Magisterial, Dogmatic, Arrogant, Domineering, Imperious, Dictatorial, Peremptory, official, grand, haughty, lordly, oracular. Authoritative is rarely used in a bad sense. Magisterial, in the sense of having the manner of a master or magistrate, generally indicates the overdoing of that manner: as, magisterial pomp and gravity. Dogmatic reaches somewhat more deeply into the character; the dogmatic man insists strenuously upon the correctness of his own opinions, and, being unable to see how others can fail to believe with him, dictatorially presses upon them his opinions as true without argument, while he tends also to blame and overbear those who venture to express dissent. (See confident.) Arrogant implies the assumption of more than due authority from an overestimate of one's importance. (See arrogance.) Domineering, imperious, and dictatorial apply to the assertion of one's own will over those of others in the attempt to rule. Domineering suggests unfitness or lack of authority to rule, with an insulting, hectoring, or bullying manner. Imperious contains most of the real power of the will, suggesting a lofty or lordly determination to be obeyed. Dictatorial implies, on the one hand, a disposition to rule, and, on the other, a sharp insistence upon having one's orders accepted or carried out. Peremptory shuts off discussion: a peremptory command or denial is one that must be obeyed or accepted to the letter and without debate; it is positive, absolute, and often immediate.

Wiktionary

1. adj. Befitting the status or skill of a magister or master; authoritative, masterly.
2. adj. Of or pertaining to a master or magistrate, or one in authority.
3. adj. Pertaining to, produced by, or of the nature of, magistery.

GNU Webster's 1913

1. adj. Of or pertaining to a master or magistrate, or one in authority; having the manner of a magister; official; commanding; authoritative. Hence: Overbearing; dictatorial; dogmatic.
2. adj. (Alchem. & Old Chem.) Pertaining to, produced by, or of the nature of, magistery. See Magistery, 2.

WordNet 3.0

1. adj. of or relating to a magistrate
2. adj. used of a person's appearance or behavior; befitting an eminent person
3. adj. offensively self-assured or given to exercising usually unwarranted power