Available Definitions:
1) adv. - From a definite past time until now; as, he went a month ago, and I have not seen him since.
2) adv. - In the time past, counting backward from the present; before this or now; ago.
3) adv. - When or that.
4) prep. - From the time of; in or during the time subsequent to; subsequently to; after; -- usually with a past event or time for the object.
5) conj. - Seeing that; because; considering; -- formerly followed by that.