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.

It’s accidental that the U.K. is more acutely unstable than the U.S.,

From The Wall Street Journal • Jun. 25, 2026

"The situation is still unstable," Abu Assi explained.

From Barron's • Jun. 22, 2026

But even the simplest moves were noticeably harder on an unstable surface.

From Los Angeles Times • Jun. 15, 2026

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

From Science Daily • Jun. 8, 2026

I’m unstable almost immediately and begin to fall backward.

From "Everything, Everything" by Nicola Yoon

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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