1 since /ˈsɪns/ preposition
1 since
Learner's definition of SINCE
: in the time after (a specified time or event in the past) : from (a point in the past) until the present time

since the year one

see year

since when?

used to show that you are surprised and often angry, annoyed, or doubtful about what someone has said or done
2 since /ˈsɪns/ conjunction
2 since
Learner's definition of SINCE
: in the period after the time when
: from the time in the past when
used to introduce a statement that explains the reason for another statement
3 since /ˈsɪns/ adverb
3 since
Learner's definition of SINCE
: from a past time until now
: after a time in the past
: before the present time
see also long since at 2long