unfamiliar

adjective

un·​fa·​mil·​iar ˌən-fə-ˈmil-yər 

: not familiar:

a

: not well-known : strange

an unfamiliar place

—often used with to

used words that were unfamiliar to me

b

: not well acquainted

unfamiliar with the subject

unfamiliarity

ˌən-fə-ˌmil-ˈyer-ə-tē 

-ˌmi-lē-ˈyer-, 

-ˈya-rə-

noun

unfamiliarly

ˌən-fə-ˈmil-yər-lē 

adverb

Synonyms of unfamiliar

• strange
• new
• novel
• unprecedented
• fresh
• original
• unknown

Examples of unfamiliar in a Sentence

He gets nervous when he is in unfamiliar surroundings.

The book is full of unfamiliar words.

Recent Examples on the Web

The man looked Chinese, like them, but his features were slightly different, unfamiliar in some way—though Shawn would not have been able to say how. — Rachel Heng, New Yorker, 4 Oct. 2026

The model had to reason about a structured but unfamiliar environment using the information available through the game’s underlying protocol. — Bojan Stojkovski, Interesting Engineering, 4 Oct. 2026

But Avalon Mayor Pro Tem Michael Ponce said most crashes involve sightseeing helicopters and private planes generally unfamiliar with the island’s unique landscape and runway, officials say. — Fedor Zarkhin, Los Angeles Times, 3 Oct. 2026

For those unfamiliar with the original study, in brief, children ages three to five were presented with a marshmallow and given two options. — Joan M. Cook, Time, 3 Oct. 2026

Word History

First Known Use

1594, in the meaning defined above

Phrases Containing unfamiliar

• unfamiliar with (something)

Rhymes for unfamiliar

• conciliar
• familiar

Kids Definition

unfamiliar

adjective

un·​fa·​mil·​iar ˌən-fə-ˈmil-yər 

1

: not well-known : strange

an unfamiliar place

2

: not well acquainted

unfamiliar with the subject

unfamiliarity

-ˌmil-ˈyar-ət-ē 

-ˌmil-ē-ˈ(y)ar-

noun