a. Of or pertaining to an author. “The authorial &unr_;we.'” Hare. [ 1913 Webster ]

v. 1. grant authorization or clearance for. Same as authorize.
Syn. -- authorize, pass, clear, permit officially. [ WordNet 1.5 ]

n. Authorship. [ R. ] [ 1913 Webster ]

adj. 1. characteristic of an absolute ruler or absolute rule; having absolute sovereignty; -- of governments or rulers; as, an authoritarian regime
Syn. -- autocratic, dictatorial, despotic, tyrannical [ WordNet 1.5 ]

2. 1 expecting unquestioning obedience: "he was imperious and dictatorial"; "the timid child of authoritarian parents"; "insufferably overbearing behavior toward the waiter"
Syn. -- dictatorial, overbearing [ WordNet 1.5 ]

n. 1. 1 behaves like a tyrant.
Syn. -- dictator [ WordNet 1.5 ]

a. 1. Having, or proceeding from, due authority; entitled to obedience, credit, or acceptance; determinate; commanding. [ 1913 Webster ]

The sacred functions of authoritative teaching. Barrow. [ 1913 Webster ]

2. Having an air of authority; positive; dictatorial; peremptory; as, an authoritative tone. [ 1913 Webster ]

The mock authoritative manner of the one, and the insipid mirth of the other. Swift. [ 1913 Webster ]

-- Au*thor"i*ta*tive*ly, adv. -- Au*thor"i*ta*tive*ness, n. [ 1913 Webster ]

n. 1. the organization that is the governing authority of a political unit.
Syn. -- government, regime. [ WordNet 1.5 ]

n.; pl. Authorities [ OE. autorite, auctorite, F. autorité, fr. L. auctoritas, fr. auctor. See Author, n. ] 1. Legal or rightful power; a right to command or to act; power exercised buy a person in virtue of his office or trust; dominion; jurisdiction; authorization; as, the authority of a prince over subjects, and of parents over children; the authority of a court. [ 1913 Webster ]

Thus can the demigod, Authority,
Make us pay down for our offense. Shak. [ 1913 Webster ]

By what authority doest thou these things ? Matt. xxi. 23. [ 1913 Webster ]

2. Government; the persons or the body exercising power or command; as, the local authorities of the States; the military authorities. [ Chiefly in the plural. ] [ 1913 Webster ]

3. The power derived from opinion, respect, or esteem; influence of character, office, or station, or mental or moral superiority, and the like; claim to be believed or obeyed; as, an historian of no authority; a magistrate of great authority. [ 1913 Webster ]

4. That which, or one who, is claimed or appealed to in support of opinions, actions, measures, etc. Hence: (a) Testimony; witness. “And on that high authority had believed.” Milton. (b) A precedent; a decision of a court, an official declaration, or an opinion, saying, or statement worthy to be taken as a precedent. (c) A book containing such a statement or opinion, or the author of the book. (d) Justification; warrant. [ 1913 Webster ]

Wilt thou be glass wherein it shall discern
Authority for sin, warrant for blame. Shak. [ 1913 Webster ]

a. [ LL. authorisabilis. ] Capable of being authorized. Hammond. [ 1913 Webster ]

n. [ Cf. F. autorisation. ] The act of giving authority or legal power; establishment by authority; sanction or warrant. [ 1913 Webster ]

The authorization of laws. Motley. [ 1913 Webster ]

A special authorization from the chief. Merivale. [ 1913 Webster ]