IPA: /ˌʌnəˈvɔɪdəbəl/
KK: /ʌnəˈvɔɪdəbəl/
Something that cannot be avoided or prevented; it is certain to happen.
The rain was unavoidable, so we decided to bring our umbrellas.
Unavoidable → It is formed from "un-" (meaning not) and "avoid" (from Latin "vacuare", meaning to empty or to make void) and "-able" (meaning capable of). The word "unavoidable" means not capable of being avoided or escaped.
Think of 'not' ('un-') being able to 'empty' or 'make void' ('vacuare') — that's why unavoidable means something you cannot escape.