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

How will my child handle new routines, unfamiliar classmates or unexpected changes? — Jennifer Durocher, Sun Sentinel, 5 Aug. 2026

Packed prematch marches stunned organizers who were unfamiliar with the tradition. — Los Angeles Times, 3 Aug. 2026

When traveling overseas, find out if rabies is prevalent and keep your distance from wild animals and unfamiliar dogs and cats. — Don Sweeney, Sacbee.com, 3 Aug. 2026

Drivers should always take caution when operating an unfamiliar vehicle to avoid mishaps and achieve optimal performance, especially with unfamiliar powertrains (hybrids, plug-in hybrids and EVs). — Charles Singh, USA Today, 3 Aug. 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