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 sender's name looks unfamiliar, but the delivery seems real. — Kurt Knutsson, FOXNews.com, 27 June 2026

Compared with many families, parents of autistic children often devote considerably more time and emotional energy to planning because unfamiliar environments, changes in routine, and sensory experiences can create anxiety. — Jennifer Jay Palumbo, Forbes.com, 26 June 2026

One of their most accessible options, though, might feel unfamiliar to anyone accustomed to central air. — Beth Gardiner, The Atlantic, 26 June 2026

But Brady, perhaps the league’s most famous sixth-round pick, is unfamiliar with the burden that comes with being the top selection. — Sam Warren, New York Times, 25 June 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