The Collaborative International Dictionary of English v.0.48:

Author \Au"thor\ ([add]"th[~e]r), n. [OE. authour, autour, OF.
   autor, F. auteur, fr. L. auctor, sometimes, but erroneously,
   written autor or author, fr. augere to increase, to produce.
   See Auction, n.]
   1. The beginner, former, or first mover of anything; hence,
      the efficient cause of a thing; a creator; an originator.
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            Eternal King; thee, Author of all being. --Milton.
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   2. One who composes or writes a book; a composer, as
      distinguished from an editor, translator, or compiler.
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            The chief glory of every people arises from its
            authors.                              --Johnson.
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   3. The editor of a periodical. [Obs.]
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   4. An informant. [Archaic] --Chaucer.
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The Collaborative International Dictionary of English v.0.48:

Author \Au"thor\ ([add]"th[~e]r), v. t.
   1. To occasion; to originate. [Obs.]
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            Such an overthrow . . . I have authored. --Chapman.
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   2. To tell; to say; to declare. [Obs.]
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            More of him I dare not author.        --Massinger.
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WordNet (r) 3.0 (2006):

author
    n 1: writes (books or stories or articles or the like)
         professionally (for pay) [syn: writer, author]
    2: someone who originates or causes or initiates something; "he
       was the generator of several complaints" [syn: generator,
       source, author]
    v 1: be the author of; "She authored this play"