inconceivable

adjective

in·​con·​ceiv·​able ˌin-kən-ˈsē-və-bəl 

: not conceivable: such as

a

: unbelievable

It's inconceivable they survived the crash.

b

: impossible to comprehend

… a work of inconceivable difficulty and labour …

—Mary W. Shelley

inconceivability

ˌin-kən-ˌsē-və-ˈbi-lə-tē 

noun

inconceivableness

ˌin-kən-ˈsē-və-bəl-nəs 

noun

inconceivably

ˌin-kən-ˈsē-və-blē 

adverb

Synonyms of inconceivable

• incredible
• incredulous
• unlikely
• impossible
• unthinkable
• unimaginable
• unbelievable

Examples of inconceivable in a Sentence

The fire caused an inconceivable amount of damage.

After coming this far, to quit now would be inconceivable.

Recent Examples on the Web

In the 1990s, when Jackson and a bipartisan coalition reframed Africa as strategic terrain rather than charitable afterthought, dismantling that infrastructure would have been politically inconceivable. —Alexanderia Baker-Haidara, semafor.com, 27 Feb. 2026

Until recently, this nightmarish scenario for Democrats seemed inconceivable. —George Skelton, Mercury News, 25 Feb. 2026

With the exponential rise of deranged talking heads, private prisons, Amazon-like concentration camps, Cop City, local police trained by the Israeli Army, and AI technology to develop inconceivable weapons, the apocalypse does not appear far off. —Literary Hub, 19 Feb. 2026

What seemed inevitable for Ilia Malinin became inconceivable. —Bora Erden, New York Times, 14 Feb. 2026

Word History

First Known Use

1624, in the meaning defined above

Rhymes for inconceivable

• achievable
• believable
• conceivable
• perceivable
• receivable
• retrievable
• irretrievable
• unbelievable

Kids Definition

inconceivable

adjective

in·​con·​ceiv·​able ˌin-kən-ˈsē-və-bəl 

: impossible to imagine or believe

inconceivably

-blē 

adverb