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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.

Researchers found that Latino students faced myriad challenges, including immigration issues, English proficiency and unstable housing that is linked to their parents’ employment status.

From Los Angeles Times • Apr. 1, 2026

But Franziska Brantner from Germany's opposition Green Party said returning to Syria was not an option for many, because of the lack of infrastructure and the unstable security situation there.

From BBC • Mar. 30, 2026

The best a dictionary can do is map that unstable terrain for a moment.

From The Wall Street Journal • Mar. 27, 2026

These conflicting tendencies force the system into an unstable state.

From Science Daily • Mar. 22, 2026

"Appropriately," notes Paul Strathern, "it is an unstable element."

From "A Short History of Nearly Everything" by Bill Bryson

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.