be‧fore1 S1 W1
earlier than a particular event or action [≠ after]: ➔ see usage note ago
Say goodbye before you go.
I saw her a few days before she died.
so that something does not or cannot happen:
Put that money somewhere safe before it gets stolen.
That dog ought to be destroyed before it attacks any more children.
Before I could say anything more, Holmes had rushed off towards the station.
used to say that something happens after a period of time:
It was several minutes before we realised what was happening.
It will be a while before we know the results.
used to say that something must happen in order for something else to be possible:
You have to pass a test before you can get a licence.
used to warn someone that something bad will happen to them if they do not do something:
Get out before I call the police!
used to emphasize that someone does not want to do something:
She would die before she would admit she was wrong.