Meaning: Saved by the Bell
When to use: Its meaning is to avoid doing something, usually that is unpleasant or make you nervous.
Where is coming from: The origin comes from many, many years ago, when medicine was so little advanced. Sometimes people who had suffered a catalepsy or dizziness were taken as dead. When scratches were discovered in the coffins, people found out that the person was buried alive.
Because of this situation, it was decided to put a bell on the outside of the coffin, joined by a rope to the hand of the person inside. This way they can take him out of such claustrophobic confinement and not die buried alive.