Meaning of the word "First of all" in English

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

First of all

US /fɜrst əv ɔl/
UK /fɜrst əv ɔl/

Phrase

before anything else; above all

Example:
First of all, I want to thank everyone for coming.
You need to finish your homework, first of all.