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definitions

since

[sins]
See more synonyms for since on Thesaurus.com
adverb
  1. from then till now (often preceded by ever): He was elected in 1978 and has been president ever since.
  2. between a particular past time and the present; subsequently: She at first refused, but has since consented.
  3. ago; before now: long since.
preposition
  1. continuously from or counting from: It has been warm since noon.
  2. between a past time or event and the present: There have been many changes since the war.
conjunction
  1. in the period following the time when: He has written once since he left.
  2. continuously from or counting from the time when: He has been busy since he came.
  3. because; inasmuch as: Since you're already here, you might as well stay.

Origin of since

1400–50; late Middle English syns, sinnes (adv.) thereupon, afterwards, Middle English sithenes (adv. and conjunction) afterwards, from (the specified time), because, equivalent to sithen after that, since (Old English siththan, orig. sīth thām after that; see sith) + -es -s1

Synonym study

8. See because.

Usage note

8. See as1.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for since

ago, therefore, already, afterward, later, considering, for, as, after, following, because, from, hence, now, past, subsequently, whereas
British Dictionary definitions for since

since

preposition
  1. during or throughout the period of time aftersince May it has only rained once
conjunction (subordinating)
  1. (sometimes preceded by ever) continuously from or starting from the time whensince we last met, important things have happened
  2. seeing that; becausesince you have no money, you can't come
adverb
  1. since that timehe left yesterday and I haven't seen him since

Word Origin for since

Old English sīththan, literally: after that; related to Old High German sīd since, Latin sērus late

xref

See ago
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for since
adv.

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.

Online Etymology Dictionary, © 2010 Douglas Harper
Idioms and Phrases with since

since

see greatest thing since sliced bread.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.