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.

Einstein–Rosen bridges are therefore unstable and unobservable — mathematical structures, not portals.

From Science Daily • May 22, 2026

A Hypershell spokesman said that a snug, proper fit and a lower level of assistance can help on unstable terrain.

From The Wall Street Journal • May 21, 2026

There are unstable layers of debt at the firm, fund and investor level.

From MarketWatch • May 20, 2026

Mohammadi's Paris-based husband said "she is not in a favourable general condition" and that "her status remains unstable", in a statement over the weekend.

From BBC • May 10, 2026

Can you imagine a beast so mean, unstable, and stinky that even pirates had kicked him off their ship?

From "The Many Assassinations of Samir, the Seller of Dreams" by Daniel Nayeri

Vocabulary lists containing unstable

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Engineering - Introductory

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