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.

They were more resistant to drying out, which would have been crucial in the dry and unstable climate following the mass extinction.

From Science Daily • Apr. 14, 2026

Maybe she’s concerned that he could become financially unstable and a burden to her if he gives away too much.

From MarketWatch • Apr. 13, 2026

They also share other concerns: militants and the "unstable" Afghanistan.

From BBC • Apr. 10, 2026

Even if the world’s governments manage to bring down carbon emissions in the next 25 years, scientists expect the climate to become much more unstable because of the damage that’s already been done.

From The Wall Street Journal • Apr. 6, 2026

The blast also created radioactive atoms—atoms with unstable nuclei that break apart, ejecting particles and rays as they decay.

From "Fallout: Spies, Superbombs, and the Ultimate Cold War Showdown" by Steve Sheinkin

Vocabulary lists containing unstable

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Engineering - Introductory

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Civil Engineering

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