Source : Webster's Revised Unabridged Dictionary (1913)

Fair \Fair\, a. [Compar. {Fairer}; superl. {Fairest}.] [OE.
   fair, fayer, fager, AS. f[ae]ger; akin to OS. & OHG. fagar,
   Icel. fagr, Sw. fager, Dan. faver, Goth. fagrs fit, also to
   E. fay, G. f["u]gen, to fit. fegen to sweep, cleanse, and
   prob. also to E. fang, peace, pact, Cf. {Fang}, {Fain}, {Fay}
   to fit.]
   1. Free from spots, specks, dirt, or imperfection;
      unblemished; clean; pure.

            A fair white linen cloth.             --Book of
                                                  Common Prayer.

   2. Pleasing to the eye; handsome; beautiful.

            Who can not see many a fair French city, for one
            fair French made.                     --Shak.

   3. Without a dark hue; light; clear; as, a fair skin.

            The northern people large and fair-complexioned.
                                                  --Sir M. Hale.

   4. Not overcast; cloudless; clear; pleasant; propitious;
      favorable; -- said of the sky, weather, or wind, etc.; as,
      a fair sky; a fair day.

            You wish fair winds may waft him over. --Prior.

   5. Free from obstacles or hindrances; unobstructed;
      unincumbered; open; direct; -- said of a road, passage,
      etc.; as, a fair mark; in fair sight; a fair view.

            The caliphs obtained a mighty empire, which was in a
            fair way to have enlarged.            --Sir W.
                                                  Raleigh.

   6. (Shipbuilding) Without sudden change of direction or
      curvature; smooth; fowing; -- said of the figure of a
      vessel, and of surfaces, water lines, and other lines.

   7. Characterized by frankness, honesty, impartiality, or
      candor; open; upright; free from suspicion or bias;
      equitable; just; -- said of persons, character, or
      conduct; as, a fair man; fair dealing; a fair statement.
      ``I would call it fair play.'' --Shak.

   8. Pleasing; favorable; inspiring hope and confidence; --
      said of words, promises, etc.

            When fair words and good counsel will not prevail on
            us, we must be frighted into our duty. --L'
                                                  Estrange.

   9. Distinct; legible; as, fair handwriting.

   10. Free from any marked characteristic; average; middling;
       as, a fair specimen.

             The news is very fair and good, my lord. --Shak.

   {Fair ball}. (Baseball)
       (a) A ball passing over the home base at the height
           called for by the batsman, and delivered by the
           pitcher while wholly within the lines of his position
           and facing the batsman.
       (b) A batted ball that falls inside the foul lines; --
           called also a {fair hit}.

   {Fair maid}. (Zo["o]l.)
       (a) The European pilchard ({Clupea pilchardus}) when
           dried.
       (b) The southern scup ({Stenotomus Gardeni}). [Virginia]
           

   {Fair one}, a handsome woman; a beauty,

   {Fair play}, equitable or impartial treatment; a fair or
      equal chance; justice.

   {From fair to middling}, passable; tolerable. [Colloq.]

   {The fair sex}, the female sex.

   Syn: Candid; open; frank; ingenuous; clear; honest;
        equitable; impartial; reasonable. See {Candid}.

Source : WordNet®

fair ball
     n : (baseball) a ball struck with the bat so that it stays
         between the lines (the foul lines) that define the width
         of the playing field [ant: {foul ball}]