since

UK: /ˈsɪns/ US: /sɪns/ ,(sins)

WordReference Random House Learner's Dictionary of American English © 2026

since /sɪns/   adv. 

1. from then till now (often preceded by ever ):
   Those elected in 1990 have been on the committee ever since.
2. between a particular past time and the present;
   subsequently:
   She at first refused, but has since consented.
3. ago;
   before now:
   She has long since left him; didn't you know?

prep. 

4. starting continuously from or counting from:
   It has been raining since noon.
5. between a past event and the present:
   There have been many changes since the war.

conj. 

6. in the period following the time when:
   He has written once since he left.
7. continuously from or counting from the time when:
   I've been busy since I arrived.
8. because;
   inasmuch as:
   Since you've been here awhile, you might as well stay.

Usage

The word since very often appears with a verb in the present perfect tense, that is, with has or have plus the -ed/-en form of the main verb.

WordReference Random House Unabridged Dictionary of American English © 2026

since  (sins), adv. 

1. from then till now (often prec. 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.

prep. 

4. continuously from or counting from:
   It has been warm since noon.
5. between a past time or event and the present:
   There have been many changes since the war.

conj. 

6. in the period following the time when:
   He has written once since he left.
7. continuously from or counting from the time when:
   He has been busy since he came.
8. because;
   inasmuch as:
   Since you're already here, you might as well stay.

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

Synonyms

• 8. See because. 

Usage

8. See as ¹.

Collins Concise English Dictionary © HarperCollins Publishers::

since / sɪns/ preposition

1. during or throughout the period of time after: since May it has only rained once

conjunction (subordinating)

1. (sometimes preceded by ever) continuously from or starting from the time when
2. seeing that; because

adverb

1. since that time: he left yesterday and I haven't seen him since

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