unnatural

adjective

un·​nat·​u·​ral ˌən-ˈna-chə-rəl 

-ˈnach-rəl

1

: not being in accordance with nature or consistent with a normal course of events

It seemed unnatural to keep the bird in a cage.

2

a

: not being in accordance with normal human feelings or behavior

an unnatural devotion to money

b

: lacking ease and naturalness : contrived

her manner was forced and unnatural

c

: inconsistent with what is reasonable or expected

an unnatural alliance

unnaturally

ˌən-ˈna-chə-rə-lē 

-ˈnach-rə-, 

-ˈna-chər-

adverb

unnaturalness

ˌən-ˈna-chə-rəl-nəs 

-ˈnach-rəl-

noun

Synonyms of unnatural

• abnormal

Choose the Right Synonym for unnatural

irregular, anomalous, unnatural mean not conforming to rule, law, or custom.

irregular implies not conforming to a law or regulation imposed for the sake of uniformity in method, practice, or conduct.

concerned about his irregular behavior

anomalous implies not conforming to what might be expected because of the class or type to which it belongs or the laws that govern its existence.

her drive made her an anomalous figure in a sleepy organization

unnatural suggests what is contrary to nature or to principles or standards felt to be essential to the well-being of civilized society.

prisoners treated with unnatural cruelty

Examples of unnatural in a Sentence

It seems unnatural to keep the bird in a cage.

She has an unnatural obsession with money.

Her smile looked forced and unnatural.

Recent Examples on the Web

The biggest factor separating natural from unnatural results is judgment, knowing how much is enough and when to stop. —Carlos Wolf, Miami Herald, 12 Mar. 2026

Some swim-current systems can create uneven or turbulent flow, which can make swimming feel unnatural. —New Atlas, 12 Mar. 2026

As his band’s popularity and star power rise, so does Lestat’s influence over vampires and humans alike, leaving others to contend with Lestat’s power in the face of the Great Conversion, an unnatural surge in the vampire population. —Rosy Cordero, Deadline, 12 Mar. 2026

The latter is popular with professionals for its colorful adjuster shades—liquid pigments in unnatural colors that can alter the tone of your base. —Sophia Panych, Allure, 11 Mar. 2026

Word History

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing unnatural

• unnatural causes

Rhymes for unnatural

• natural
• preternatural
• supernatural

Kids Definition

unnatural

adjective

un·​nat·​u·​ral ˌən-ˈnach-(ə-)rəl 

ˈən-

1

: not following nature or a normal course of events

2

a

: not being in agreement with normal feelings or behavior

b

: lacking ease and naturalness

unnaturally

-ˈnach-(ə-)rə-lē 

-ˈnach-ər-lē

adverb

unnaturalness

-ˈnach-(ə-)rəl-nəs 

noun