inconceivable

adjective

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

: not conceivable: such as

a

: unbelievable

b

: impossible to comprehend

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

• incredible
• incredulous
• unlikely
• impossible
• unthinkable
• unimaginable
• fantastical
• 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 mid-’90s, broadcast networks dominated prime time with megahits like Seinfeld, ER, and The X-Files, whose viewership on Fox peaked at a now-inconceivable 20 million. —Judy Berman, Time, 27 Oct. 2025

The journey there today regularly incorporates creature comforts that were inconceivable even two decades ago. —Brad Japhe, HollywoodReporter, 25 Oct. 2025

Coach Matt Eberflus lost his job after the sixth straight loss, in late November, having gone an almost inconceivable 5-19 in one-score games during his tenure as Chicago’s head coach. —David Aldridge, New York Times, 12 Oct. 2025

Building or expanding power plants to generate that much electricity on Altman’s timetable indeed seems almost inconceivable. —Eleanor Pringle, Fortune, 11 Oct. 2025

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