Thesaurus

unstable

adjective

Synonyms & Antonyms of unstable

1 not being in or able to maintain a state of balance
  • the minute we put the books down on the unstable desk, the whole stack went crashing to the floor

Synonyms for unstable

Words Related to unstable

Near Antonyms for unstable

Antonyms for unstable

3 not staying constant
  • unstable temperatures are not ideal storage conditions for wine

Synonyms for unstable

Words Related to unstable

Near Antonyms for unstable

Antonyms for unstable

See the Dictionary Definition 

Frequently Asked Questions About unstable

How does the adjective unstable differ from other similar words?

Some common synonyms of unstable are capricious, fickle, inconstant, and mercurial. While all these words mean "lacking firmness or steadiness (as in purpose or devotion)," unstable implies an incapacity for remaining in a fixed position or steady course and applies especially to a lack of emotional balance.

too unstable to hold a job

When can capricious be used instead of unstable?

The synonyms capricious and unstable are sometimes interchangeable, but capricious suggests motivation by sudden whim or fancy and stresses unpredictability.

an utterly capricious critic

When would fickle be a good substitute for unstable?

The words fickle and unstable can be used in similar contexts, but fickle suggests unreliability because of perverse changeability and incapacity for steadfastness.

performers discover how fickle fans can be

When is inconstant a more appropriate choice than unstable?

The words inconstant and unstable are synonyms, but do differ in nuance. Specifically, inconstant implies an incapacity for steadiness and an inherent tendency to change.

an inconstant friend

When could mercurial be used to replace unstable?

Although the words mercurial and unstable have much in common, mercurial implies a rapid changeability in mood.

made anxious by her boss's mercurial temperament

Keep scrolling for more

Learn More about unstable

Time Traveler for unstable

Time Traveler

The first known use of unstable was in the 13th century

See more words from the same century

Cite this Entry

“Unstable.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unstable. Accessed 19 Oct. 2020.

Keep scrolling for more

More from Merriam-Webster on unstable

Dictionary: Definition of unstable

Medical Dictionary: Definition of unstable

Nglish: Translation of unstable for Spanish Speakers

Comments on unstable

What made you want to look up unstable? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

Test Your Vocabulary

Farm Idioms Quiz

  • cow coming home
  • What does 'poke' refer to in the expression 'pig in a poke'?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Add Diction

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!