improbability

C2+ Topic:Abstract Ideas

US /ɪmˌprɑbəˈbɪləti/ UK /ɪmˌprɒbəˈbɪləti/ See IPA manual

Meanings

1

noun
the quality of being unlikely to be true or to happen

Despite the improbability of success, they pressed on with the rescue.

Thesaurus

Synonyms

1 noun · the quality of being... unlikelihoodimplausibilitydoubtfulness incredibility

Opposites

probability likelihood certainty

Word family

Related forms improbable probable probability

Etymology

From in- ('not') + probability, from Latin probabilitas, from probabilis ('provable, credible'), from probare ('to test, prove'), from probus ('good, upright').

probabilis Latin probare Latin

View etymology graph ->

Topics

Abstract Ideas Word Formation & Derivatives

External links

# improbability

**Type:** Word
**Level:** C2+
**Part of speech:** noun
**IPA (US):** /ɪmˌprɑbəˈbɪləti/
**IPA (UK):** /ɪmˌprɒbəˈbɪləti/

## Meanings
1. the quality of being unlikely to be true or to happen

## Examples
- Despite the improbability of success, they pressed on with the rescue.

## Synonyms
- unlikelihood
- implausibility
- doubtfulness
- incredibility

## Antonyms
- probability
- likelihood
- certainty

## Related Forms
- improbable
- probable
- probability

## Roots and Affixes
- Root: probabilis
- Root: probare

## Etymology
From in- ('not') + probability, from Latin probabilitas, from probabilis ('provable, credible'), from probare ('to test, prove'), from probus ('good, upright').

## AI Etymology
improbability comes from in- ('not') + probability, from Latin probabilitas, from probabilis ('provable, credible'), from probare ('to test, prove'), from probus ('good, upright'). Morphologically, the prefixed shape matters: the initial element belongs to the recorded formation and helps explain the modern form's surface analysis. In present English, the noun sense is "the quality of being unlikely to be true or to happen", so the historical development ends in a clearly identifiable modern dictionary use. The same base also appears in related forms such as improbable, probable, and probability. Its semantic neighborhood includes unlikelihood, implausibility, doubtfulness, and incredibility, which helps locate the modern sense without adding a separate etymological claim. The named historical forms include Latin probabilis and Latin probare.

## Topics
- Abstract Ideas
- Word Formation & Derivatives

markdown