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.

Though Mr. Vile plays many of the instruments, the tracks feel communal, intimate and spontaneous.

From The Wall Street Journal • Jun. 2, 2026

Base told Rolling Stone in a 2014 interview the song's creation was spontaneous and he was shocked by its success.

From BBC • May 23, 2026

Most cancers are spontaneous and can’t be detected in a genetic test.

From Barron's • May 21, 2026

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

From Science Daily • May 10, 2026

The cheerleaders erupted into a spontaneous little cheer of “Midland High, yeah, Midland High!” and then Air Force II came into view.

From "Friday Night Lights: A Town, A Team, And A Dream" by H.G. Bissinger

Vocabulary lists containing spontaneous

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