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.
2. In order that; that. [Obs.]
And the multitude rebuked them because they should
hold their peace. --Matt. xx.
Because of, by reason of, on account of. [Prep. phrase.]
Because of these things cometh the wrath of God upon
the children of disobedience. --Eph. v. 6.
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.
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,