I. ˈsin(t)s adverb
Etymology: Middle English sins, contraction of sithens, from sithen, from Old English siththan, from sīth tham after that, from sīth after, late + tham, dative of thæt that; akin to Old High German sīd later and perhaps to Latin setius to a lesser degree
Date: 15th century
1. : from a definite past time until now
has stayed there ever since
2. : before the present time : ago
long since dead
3. : after a time in the past : subsequently
has since become rich
II. conjunction
Date: 15th century
1. : at a time in the past after or later than
has held two jobs since he graduated
: from the time in the past when
ever since I was a child
2. obsolete : when
3. : in view of the fact that : because
since it was raining she took an umbrella
III. preposition
Date: circa 1530
: in the period after a specified time in the past : from a specified time in the past