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.

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

She began calling up private ambulance companies, but they would not agree to drive Waldorf because they considered her condition unstable.

From Salon • May 27, 2026

Their analysis revealed another unstable stage in the process, a single ring-slipped intermediate that forms from the doubly ring-slipped structure.

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

“Sorry, it’s all I’ve got. Anyway, potassium chlorate is unstable under heat and pressure. It's too dangerous for rocket fuel. What do your parents think about the BCMA?”

From "October Sky" by Homer Hickam

Vocabulary lists containing unstable

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