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

Local police routinely receive extensive instruction in traffic stops, neighborhood patrol, crisis intervention, de-escalation, and managing unpredictable encounters with the public. — Sun Sentinel Editorial Board, Sun Sentinel, 19 July 2026

The physics remain loose and unpredictable so plenty of spectacular failures await, but with one person doing the attempts at group coordination and inevitable screw-ups. — Jason Bennett, Arkansas Online, 19 July 2026

Natural bodies of water can be unpredictable, and life jackets provide an important layer of protection even for people who are confident swimmers. — Katia Hetter, CNN Money, 18 July 2026

The ensemble drama traces the unpredictable shape of grief and family dynamics, aiming for an emotionally candid portrait of loss and the ties that hold communities together. — Naman Ramachandran, Variety, 17 July 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