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

Conspiracy theorists have proposed many different (though mostly superstitious and inconceivable) reasons why disappearances and disasters occur in the Bermuda Triangle. — Andrea Romano, Travel + Leisure, 15 July 2026

And the power play was 17th in the NHL, which seems inconceivable for a team with as much offensive firepower as Tampa Bay. — Scott Turick, The Orlando Sentinel, 11 July 2026

Poland has reportedly been warned by the United States that Moscow might attack – in a limited fashion, perhaps with drones or another form of hybrid warfare, but still in a way that decades ago would have seemed inconceivable. — Nick Paton Walsh, CNN Money, 6 July 2026

This would be inconceivable in other sporting cultures around the world. — Patrick Iversen, New York Times, 6 July 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