unpredictable

adjective

un·​pre·​dict·​able ˌən-pri-ˈdik-tə-bəl 

: not predictable: such as

a

: not able to be known or declared in advance

unpredictable weather

b

: tending to behave in ways that cannot be predicted

an unpredictable boss

unpredictably

ˌən-pri-ˈdik-tə-blē 

adverb

changes that occur unpredictably

unpredictability

ˌən-pri-ˌdik-tə-ˈbi-lə-tē 

noun

the unpredictability of the weather

Synonyms of unpredictable

• volatile
• changeful
• unstable

Examples of unpredictable in a Sentence

unpredictable spring weather that makes it really hard to know what to wear

Recent Examples on the Web

In the series, Bardem portrays Max Cady, the unpredictable, charismatic ex-con embodied in 1991's Cape Fear by De Niro, who earned an Oscar nomination for his performance in the film. —Wesley Stenzel, Entertainment Weekly, 25 May 2026

These should move beyond unpredictable and short-term premiums and prioritise true collaboration by blending local insight with strategic direction, instead of a largely top-down model. —Indrabati Lahiri, Forbes.com, 25 May 2026

This reliance on high-energy processing and rigid programming fundamentally limits operation in unpredictable, real-world settings. —Mrigakshi Dixit, Interesting Engineering, 25 May 2026

Sepsis can be unpredictable, and that’s why early recognition matters so much. —Dr. Jamin Brahmbhatt, CNN Money, 24 May 2026

Word History

First Known Use

1840, in the meaning defined above

Rhymes for unpredictable

• indictable
• predictable

Kids Definition

unpredictable

adjective

un·​pre·​dict·​able

ˌən-pri-ˈdik-tə-bəl

: not predictable

unpredictability

-ˌdik-tə-ˈbil-ət-ē

noun

unpredictably

-ˈdik-tə-blē

adverb