Meaning of the word "in a flash" in English

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

in a flash

US /ɪn ə flæʃ/
UK /ɪn ə flæʃ/

Idiom

very quickly or suddenly

Example:
The car disappeared in a flash.
I'll be there in a flash.