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.

This is the 17th Ebola outbreak to hit the DRC, a vast and unstable central African country of more than 100 million people.

From Barron's • Jun. 8, 2026

But over the short and even intermediate terms, lasting not just several years but decades, gold’s correlation to inflation is unstable.

From MarketWatch • Jun. 8, 2026

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

From Science Daily • May 30, 2026

About 90,000 gallons of the chemical is left in the tank and remains unstable, complicating recovery efforts, said Scott Goldstein, chief of Cowlitz 2 Fire & Rescue.

From The Wall Street Journal • May 27, 2026

Little kids in particular were too inherently unstable.

From "The School for Whatnots" by Margaret Peterson Haddix

Vocabulary lists containing unstable

100 SAT Words Beginning with "U"

Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!

Engineering - Introductory

Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!

Civil Engineering

Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!