spontaneous

[spon-tey-nee-uhs] / spɒnˈteɪ ni əs /

ADJECTIVE

impulsive, willing

Synonyms

STRONGEST

casual impromptu instinctive offhand simple unplanned voluntary

WEAK

ad-lib automatic break loose down extemporaneous extempore free free-spirited from the hip impetuous improvised inevitable involuntary irresistible natural off top of head off-the-cuff unartful unavoidable unbidden uncompelled unconscious unconstrained uncontrived uncontrolled unforced unintentional unpremediated unprompted unsophisticated unstudied up front

Antonyms

STRONGEST

deliberate planned

WEAK

intended premeditated

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.

“In his zealous and highly scrutinized representation, Dershowitz made a spontaneous series of remarks before Congress that, he says, were misinterpreted by pundits,” Judge Britt Grant, a Trump appointee wrote for the 11th Circuit Court.

From Los Angeles Times • Jun. 29, 2026

While restaurant and bar hangouts can be spontaneous, dinner parties require more thought and planning.

From Salon • Jun. 21, 2026

He took up the spontaneous change in assignment because he "wanted to earn some extra money", HTA manager Angfurba Sherpa tells the BBC.

From BBC • Jun. 10, 2026

They also showed stronger protection against spontaneous tumors and chemically induced skin cancer.

From Science Daily • May 10, 2026

They’d found it worked on Nico better than nectar, helping to cleanse the fatigue and darkness from his system with less danger of spontaneous combustion.

From "Blood of Olympus" by Rick Riordan

Vocabulary lists containing spontaneous

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