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 work is unfamiliar and seems risky, in precisely the ways advanced mathematics or learning to read complex texts may have seemed foreign to our agricultural-era counterparts. — Tim Knowles, Fortune, 8 July 2026

Entering new markets can trigger unfamiliar regulatory obligations. — Blake Harris, Forbes.com, 8 July 2026

The three most common triggers included fear of strange people, fear of unfamiliar dogs and fear of unfamiliar situations like unexpected noises or objects on the sidewalk. — Ryan Brennan, Fort Worth Star-Telegram, 7 July 2026

The Round of 16 is not unfamiliar territory for Switzerland – this is its fourth consecutive appearance at this stage – but victory over Colombia would see the central Europeans return to the quarterfinals for the first time since 1954. — Ben Church, CNN Money, 7 July 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