spontaneous

The word “spontaneous” means happening or done without planning, on impulse. In plain terms, unplanned, natural, done on the spur of the moment.

“Spontaneous” is pronounced spon-TAY-nee-uhs (/spɑnˈteɪ.ni.əs/ in IPA).

Here is “spontaneous” used in a sentence: “They decided on a spontaneous weekend trip to the coast.”

“Spontaneous” is an adjective.

The word “spontaneous” comes from Late Latin. A learned borrowing from Late Latin spontaneus, "voluntary" — from sponte, "of one's own accord.".

“Spontaneous” is an uncommon word in modern English, usually learned at around the C1 level.

“Spontaneous” has 2 distinct senses listed in this dictionary. The most common is: happening or done without planning, on impulse.

"Spontaneous" describes something happening without planning, often in a positive or lighthearted way, like a spontaneous road trip. "Impulsive" often carries a more negative connotation, suggesting a lack of thought about consequences, such as an impulsive purchase someone regrets. Spontaneous actions can be impulsive, but the word itself is more neutral or even favourable.

In science, "spontaneous" describes something occurring naturally without external cause or human intervention, such as spontaneous combustion or a spontaneous chemical reaction. This differs from the everyday sense of doing something on impulse. Both meanings share the idea of something happening on its own, without deliberate outside triggering.

Yes, calling someone "spontaneous" usually means they are prone to acting on impulse or making unplanned decisions, often seen as a positive trait linked to fun or adventurousness. It contrasts with being highly organized or predictable. This usage draws on the first sense of the word, about acting without planning.