- from then till now (often preceded by ever): He was elected in 1978 and has been president ever since.
- between a particular past time and the present; subsequently: She at first refused, but has since consented.
- ago; before now: long since.
- continuously from or counting from: It has been warm since noon.
- between a past time or event and the present: There have been many changes since the war.
- in the period following the time when: He has written once since he left.
- continuously from or counting from the time when: He has been busy since he came.
- because; inasmuch as: Since you're already here, you might as well stay.
Origin of since
- during or throughout the period of time aftersince May it has only rained once
- (sometimes preceded by ever) continuously from or starting from the time whensince we last met, important things have happened
- seeing that; becausesince you have no money, you can't come
- since that timehe left yesterday and I haven't seen him since
Word Origin and History for since
early 15c., synnes, from sithenes "since," from sithen (plus adverbial genitive -es), from Old English siððan "afterward, from now on, hereafter, further, later, as soon as, after that," originally sið ðan "after that," from sið "after" (see sith) + ðan, weakened form of ðam, dative of ðæt (see that).
As a conjunction from late 14c.; as a preposition from 1510s; "from the time when," hence "as a consequence of the fact that." Modern spelling replaced syns, synnes 16c. to indicate voiceless final -s- sound. Since when? often expressing incredulity, is from 1907.