Meaning of the word "be about to" in English

What does "be about to" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

be about to

US /bi əˈbaʊt tuː/
UK /bi əˈbaʊt tuː/

Idiom

to be going to do something very soon

Example:
I was about to leave when the phone rang.
The movie is about to start.