To leave a place, or a gathering, without being noticed.
I'm going to try to slip away from work early, if I can.
(of time) To pass quickly, almost unnoticed.
The months slipped away and became years.
(of an advantage) To disappear; to elude one.
When Liverpool scored a third goal, their hopes of winning slipped away forever.
To die peacefully.
He slipped away quietly in his sleep.