un·fa·mil·iar 
/ˌʌnfəˈmɪljɚ/ adjective
/ˌʌnfəˈmɪljɚ/ adjective [more unfamiliar; most unfamiliar] : not frequently seen, heard, or experienced
▪ He gets nervous when he is in unfamiliar surroundings. ▪ an unfamiliar face/place ▪ The book is full of unfamiliar words. — often + to ▪ The language is unfamiliar to him. [=he does not know the language at all]
▪ He gets nervous when he is in unfamiliar surroundings. ▪ an unfamiliar face/place ▪ The book is full of unfamiliar words. — often + to ▪ The language is unfamiliar to him. [=he does not know the language at all]
unfamiliar with (something)
: not having any knowledge of something
▪ I'm unfamiliar with that subject/language.
▪ I'm unfamiliar with that subject/language.
— un·fa·mil·iar·i·ty /ˌʌnfəˌmɪlˈjerəti/ noun [noncount]
▪ His unfamiliarity with the language made the trip very challenging.
/ˌʌnfəˌmɪlˈjerəti/ noun [noncount] ▪ His unfamiliarity with the language made the trip very challenging.
