Source : Webster's Revised Unabridged Dictionary (1913)

For \For\, conj.
   1. Because; by reason that; for that; indicating, in Old
      English, the reason of anything.

            And for of long that way had walk['e]d none, The
            vault was hid with plants and bushes hoar.
                                                  --Fairfax.

            And Heaven defend your good souls, that you think I
            will your serious and great business scant, For she
            with me.                              --Shak.

   2. Since; because; introducing a reason of something before
      advanced, a cause, motive, explanation, justification, or
      the like, of an action related or a statement made. It is
      logically nearly equivalent to since, or because, but
      connects less closely, and is sometimes used as a very
      general introduction to something suggested by what has
      gone before.

            Give thanks unto the Lord; for he is good; for his
            mercy endureth forever.               --Ps. cxxxvi.
                                                  1.

            Heaven doth with us as we with torches do, Not light
            them for themselves; for if our virtues Did not go
            forth of us, 't were all alike As if we had them
            not.                                  --Shak.

   {For because}, because. [Obs.] ``Nor for because they set
      less store by their own citizens.'' --Robynson (More's
      Utopia).

   {For why}.
      (a) Why; for that reason; wherefore. [Obs.]
      (b) Because. [Obs.] See {Forwhy}.

   Syn: See {Because}.