stand by

US /stænd baɪ/
UK /stænd baɪ/
"stand by" picture
1.

to be present while something bad is happening but not do anything to stop it

:
He just stood by and watched the bullying happen.
How could you stand by and let them treat her like that?
2.

to support someone or something, especially in a difficult situation

:
I will always stand by my friends.
The company decided to stand by its decision despite public criticism.
3.

to be ready to act or to be used if needed

:
Emergency services are on stand by.
The backup generator is always on stand by in case of a power outage.