Definitions

unstable

[uhn-stey-buhl] / ʌnˈsteɪ bəl /

ADJECTIVE

doubtful

Synonyms

STRONGEST

ambiguous changeable erratic fickle insecure irrational precarious risky rocky sensitive shaky slippery ticklish tricky uncertain unpredictable unsettled unsteady volatile weak wobbly

WEAK

borderline capricious dizzy dubious fitful fluctuating giddy inconsistent inconstant lubricious mercurial mobile movable moving mutable not fixed rickety shifty suspect teetering temperamental untrustworthy vacillating variable wavering weaving wiggly

Antonyms

STRONGEST

certain clear confident constant definite dependable easy firm guarded happy predictable protected reliable safe secure sound stable steady strong sure unchanging unshaky

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The researchers believe the shipment sank during a particularly unstable period in Mediterranean history.

From Science Daily • Jun. 8, 2026

This is the 17th Ebola outbreak to hit the DRC, a vast and unstable central African country of more than 100 million people.

From Barron's • Jun. 8, 2026

But over the short and even intermediate terms, lasting not just several years but decades, gold’s correlation to inflation is unstable.

From MarketWatch • Jun. 8, 2026

About 90,000 gallons of the chemical is left in the tank and remains unstable, complicating recovery efforts, said Scott Goldstein, chief of Cowlitz 2 Fire & Rescue.

From The Wall Street Journal • May 27, 2026

He spread this rumor that the school psychologist had told his mom that Jack was emotionally unstable.

From "Auggie & Me" by R. J. Palacio

Vocabulary lists containing unstable

100 SAT Words Beginning with "U"

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Engineering - Introductory

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Civil Engineering

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