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.

Because these intermediate phases are highly unstable, they have been extremely difficult to observe directly.

From Science Daily • May 30, 2026

Hundreds of climbers are attempting to scale Mount Everest despite high costs and an unstable ice block on the key trail.

From Los Angeles Times • May 27, 2026

The job of a manager is already ridiculously unstable and the situation is getting worse every year.

From BBC • May 26, 2026

There are 82 confirmed cases and seven confirmed deaths in the vast, unstable DRC, alongside almost 750 suspected cases and 177 suspected deaths, the WHO said on Friday.

From Barron's • May 23, 2026

The sun was doing antics among the million specks of dust hanging between us and casting a brilliant, unstable pool of light on the floor.

From "A Separate Peace" by John Knowles

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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