The Collaborative International Dictionary of English v.0.48:

Because \Be*cause"\, conj. [OE. bycause; by + cause.]
   1. By or for the cause that; on this account that; for the
      reason that. --Milton.
      [1913 Webster]

   2. In order that; that. [Obs.]
      [1913 Webster]

            And the multitude rebuked them because they should
            hold their peace.                     --Matt. xx.
                                                  31.
      [1913 Webster]

   Because of, by reason of, on account of. [Prep. phrase.]
      [1913 Webster]

            Because of these things cometh the wrath of God upon
            the children of disobedience.         --Eph. v. 6.
      [1913 Webster]

   Syn: Because, For, Since, As, Inasmuch As.

   Usage: These particles are used, in certain connections, to
          assign the reason of a thing, or that "on account of"
          which it is or takes place. Because (by cause) is the
          strongest and most emphatic; as, I hid myself because
          I was afraid. For is not quite so strong; as, in
          Shakespeare, "I hate him, for he is a Christian."
          Since is less formal and more incidental than because;
          as, I will do it since you request me. It more
          commonly begins a sentence; as, Since your decision is
          made, I will say no more. As is still more incidental
          than since, and points to some existing fact by way of
          assigning a reason. Thus we say, as I knew him to be
          out of town, I did not call. Inasmuch as seems to
          carry with it a kind of qualification which does not
          belong to the rest. Thus, if we say, I am ready to
          accept your proposal, inasmuch as I believe it is the
          best you can offer, we mean, it is only with this
          understanding that we can accept it.
          [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

20 Moby Thesaurus words for "because":
   as, as long as, as things go, being, being as how, cause,
   considering, for, forasmuch as, in that, inasmuch as, insofar as,
   insomuch as, now, parce que, seeing, seeing as how, seeing that,
   since, whereas