Synonyms for Since:

adv.

therefore (adverb)
therefore, so, wherefore, thence, due to, hence, on account of, ergo, thus, owing to, thanks to, Because.

adv

therefore (adverb)
therefore, so, wherefore, thence, due to, hence, on account of, ergo, thus, owing to, thanks to, Because.

n.

early, earlier, inasmuch as, by the time, advance, as, previous, first, prior, before, barely, forasmuch as, Considering. succeeding, ensuing, beyond, after, in time, in the course of time, subsequent, subsequently, ago, following. look at, explain, precisely, nay, besides. thenceforth, meanwhile, from that day/time/moment etc. forward, meantime, ever since, henceforth, for the meantime, Thenceforward.

prep.

in the time past; because (preposition)
subsequently, hence, Because, therefore.

Other synonyms:

subsequent, meantime, succeeding, previous, barely, henceforth, Thenceforward, earlier, subsequently, forasmuch as, inasmuch as, thenceforth. following, ensuing, prior, nay, besides. early, beyond, meanwhile, first. after, precisely, explain. look at. advance. gone
ago.
in time
before.
Other relevant words:
following, beyond, Considering, ago, precisely, meantime, subsequently, subsequent, before, previous, inasmuch as, after, Thenceforward, earlier, advance, ever since, nay, forasmuch as, as, explain, meanwhile.

Usage examples for Since

  1. Since you have said it, you shall go this very night. – Myths and Folk Tales of Ireland by Jeremiah Curtin
  2. Another, was his thought- another since last week. – Greene Ferne Farm by Richard Jefferies
  3. It had been so long since the boy had told her she was here. – Lily Pearl and The Mistress of Rosedale by Ida Glenwood