Source : Webster's Revised Unabridged Dictionary (1913)

Option \Op"tion\, n. [L. optio; akin to optare to choose, wish,
   optimus best, and perh. to E. apt: cf. F. option.]
   1. The power of choosing; the right of choice or election; an
      alternative.

            There is an option left to the United States of
            America, whether they will be respectable and
            prosperous, or contemptible and miserable, as a
            nation.                               --Washington.

   2. The exercise of the power of choice; choice.

            Transplantation must proceed from the option of the
            people, else it sounds like an exile. --Bacon.

   3. A wishing; a wish. [Obs.] --Bp. Hall.

   4. (Ch. of Eng.) A right formerly belonging to an archbishop
      to select any one dignity or benefice in the gift of a
      suffragan bishop consecrated or confirmed by him, for
      bestowal by himself when next vacant; -- annulled by
      Parliament in 1845.

   5. (Stock Exchange) A stipulated privilege, given to a party
      in a time contract, of demanding its fulfillment on any
      day within a specified limit.

   {Buyer's option}, an option allowed to one who contracts to
      buy stocks at a certain future date and at a certain
      price, to demand the delivery of the stock (giving one
      day's notice) at any previous time at the market price.

   {Seller's option}, an option allowed to one who contracts to
      deliver stock art a certain price on a certain future
      date, to deliver it (giving one day's notice) at any
      previous time at the market price. Such options are
      privileges for which a consideration is paid.

   {Local option}. See under {Local}.

   Syn: Choice; preference; selection.

   Usage: {Option}, {Choice}. Choice is an act of choosing;
          option often means liberty to choose, and implies
          freedom from constraint in the act of choosing.

Source : WordNet®

option
     n 1: the right to buy or sell property at an agreed price; the
          right is purchased and if it is not exercised by a
          stated date the money is forfeited
     2: one of a number of things from which only one can be chosen;
        "what option did I have?"; "there no other alternative";
        "my only choice is to refuse" [syn: {alternative}, {choice}]
     3: the act of choosing or selecting; "your choice of colors was
        unfortunate"; "you can take your pick" [syn: {choice}, {selection},
         {pick}]

Source : Free On-Line Dictionary of Computing

option
     
        {command line option}