since
US /sɪns/
UK /sɪns/

1.
from the time when
:
•
It's been a long time since we last met.
•
Many things have changed since I left.
2.
because; as
:
•
Since you're busy, I'll leave now.
•
Since it's raining, we should stay inside.
1.
from that time until now
:
•
He moved away, and I haven't seen him since.
•
She got a new job and has been much happier since.