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.

And what better indication of the demise of the spontaneous phone call can be found?

From The Wall Street Journal • May 1, 2026

Pope Francis was often seen as a spontaneous progressive, who sometimes alienated Catholic traditionalists - for example in his restrictions on Latin Mass, which Pope Leo has eased.

From BBC • Apr. 15, 2026

"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

The Weinberg-Salam theory exhibits a property known as spontaneous symmetry breaking.

From "A Brief History of Time: And Other Essays" by Stephen Hawking

Vocabulary lists containing spontaneous

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