continuously from then until now

She has stayed there ever since

before now; ago

He should have done it long since

between then and now; subsequently

They have since become rich

in the period between (a specified past time) and now

We haven't met since 1973

from (a specified past time) until now

It's a long time since breakfast

between now and the past time when

He has held two jobs since he left school

continuously from the past time when

ever since he was a child

in view of the fact that; because

Since it was raining he wore a hat

This stamp is more interesting, since rarer