Authority, n.; pl. Authorities (.
Etymology: [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. Thus can the demigod, Authority, Make us pay down for our offense. Shak. By what authority doest thou these things Matt. xxi. 23.
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.]
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.
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. Wilt thou be glass wherein it shall discern Authority for sin, warrant for blame. Shak.
Shades of meaning
Fernald has no entry of its own for authority; he lists it under permission, precedent.
Where he writes about it:
Authority unites the right and power of control; age, wisdom, and character give authority to their possessor; a book of learned research has authority, and is even called an authority. — from permission
Authority gives a certain right of control over all that may be affected by the action. — from permission
License is a formal permission granted by competent authority to an individual to do some act or pursue some business which would be or is made to be unlawful without such permission; as, a license to preach, to solemnize marriages, or to sell intoxicating liquors. — from permission
A license is permission granted rather than authority conferred; the sheriff has authority (not permission nor license) to make an arrest. — from permission