IPA: /ʌnˈfɪl.jə/
KK: /ʌnˈfɪl.jər/
Not known or recognized; something that is new or strange to someone.
The city felt unfamiliar to her after so many years away.
Unfamiliar → It is formed from "un-" (meaning not) and "familiaris" (from Latin, meaning of a household or well-known). The word "unfamiliar" means not well-known or not recognized.
Think of 'not' ('un-') being added to 'well-known' ('familiaris') — that's why unfamilar means something that is not known to you.