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.

"Gravitational waves modulate the quantum field, which in turn affects spontaneous emission," said Jerzy Paczos, a PhD student at Stockholm University.

From Science Daily • Apr. 10, 2026

This one-sided empathy is not a spontaneous response to compelling facts, however.

From Slate • Apr. 3, 2026

You can hear people shouting and drinking and having a good time, and the crowd work is also a little more spontaneous and fun than it would be in a regular venue.

From Los Angeles Times • Mar. 27, 2026

He told Vanity Fair it was the hardest role he had played because he didn't have the "ability to improv and be spontaneous".

From BBC • Mar. 16, 2026

This myth about spontaneous combustion would be accepted as scientific fact far longer than might be imagined.

From "1919 The Year That Changed America" by Martin W. Sandler

Vocabulary lists containing spontaneous

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Animal Farm

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