Meaning of the word "non negotiable" in English

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

non negotiable

US /ˌnɑːn.nəˈɡoʊ.ʃi.ə/
UK /ˌnɒn.nəˈɡəʊ.ʃə.bəl/

Adjective

not open to discussion or modification; essential or absolute

Example:
My salary is non-negotiable.
Safety is a non-negotiable priority in this company.