Since

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