impossibility

noun

im·​pos·​si·​bil·​i·​ty (ˌ)im-ˌpä-sə-ˈbi-lə-tē 

1

: the quality or state of being impossible

the impossibility of knowing the future

2

: something impossible

The snowstorm made travel an impossibility.

Examples of impossibility in a Sentence

The blizzard made travel an impossibility.

the impossibility of knowing what the future will bring

Recent Examples on the Web

Since the Middle Ages, jurors have had to grapple with the weight of determining guilt – including having serious reservations about the quality of the evidence, the legitimacy of punishment and the impossibility of complete knowledge about the case. —Sonali Chakravarti, The Conversation, 5 May 2026

The feat was the culmination of a shift—or, perhaps more aptly, a total disruption—in marathoning over the past few years, in which the eventual breaking of the mythical two-hour mark went from an impossibility to a guarantee. —Emma Sarappo, The Atlantic, 1 May 2026

Like athletes, musicians train to master the impossibilities of decades past, to move faster, negotiate acrobatic passages with ease, reel off complex rhythms, and produce once exotic timbres. —Justin Davidson, Vulture, 29 Apr. 2026

The actual goal, Clancy argued, doesn’t need to be a balanced budget—a political and mathematical near-impossibility. —Nick Lichtenberg, Fortune, 28 Apr. 2026

Word History

First Known Use

14th century, in the meaning defined at sense 1

Rhymes for impossibility

• acceptability
• accessibility
• adaptability
• admissibility
• advisability
• affordability
• allowability
• amenability
• amiability
• appealability
• applicability
• availability

Kids Definition

impossibility

noun

im·​pos·​si·​bil·​i·​ty (ˌ)im-ˌpäs-ə-ˈbil-ət-ē 

plural impossibilities

1

: the quality or state of being impossible

2

: something impossible

Legal Definition

impossibility

noun

im·​pos·​si·​bil·​i·​ty

plural impossibilities

1

: the quality or state of being impossible

also : the affirmative defense that something (as performance) is impossible

2

: something impossible

3

: impossibility of performance in this entry

— factual impossibility

: impossibility based on factual circumstances

specifically : a partial defense to criminal liability based on the incompletion of an intended criminal act

Note: Factual impossibility is not a complete defense and does allow prosecution for attempt or for another inchoate offense. For example, if the defendant constructed a bomb that failed to explode, factual impossibility would be a defense against murder charges, but not attempted murder.

— impossibility of performance

: a doctrine in contract law that a party may be released from liability for breach of contract for failing to perform an obligation that is rendered impossible by uncontrollable circumstances (as death or failure of the means of delivery)

: a defense to breach of contract or a basis for release from contractual obligations because of impossibility of performance compare frustration, impracticability

— legal impossibility

: impossibility based on or with reference to a law

specifically : a complete defense to criminal liability based on the commitment of acts that are not criminal or illegal

Note: Legal impossibility is founded on the principle that an act is not a crime unless there is a law prohibiting it.