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.

Developing a robust offshore wind industry provides resilience in the face of an unstable global energy market.

From Salon • May 9, 2026

In April, a record 35 candidates ran for president of the chronically unstable Andean nation, which has burned through eight presidents in the past decade, four of whom were impeached.

From Barron's • May 8, 2026

She expects an unstable climate to usher in an age of private weather control.

From The Wall Street Journal • Apr. 30, 2026

While fluid membranes support fusion, they can also become unstable during freeze-thaw-induced stress, leading to leakage.

From Science Daily • Apr. 29, 2026

The room was unstable unless I looked at some fixed point.

From "The Sun Also Rises" by Ernest Hemingway

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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