Meaning & Definition
adverb
in a way that is spontaneous; occurring without external cause or planning.
The crowd began to cheer spontaneously when the home team scored.
naturally; without premeditation.
They spontaneously decided to take a road trip with no prior arrangements.
impulsively; as a response to immediate feelings.
She spontaneously invited her friends over for dinner after feeling inspired to cook.
Etymology
From the Latin 'spontaneus' meaning 'of one's own accord', from 'sponte' meaning 'of free will'.
Common Phrases and Expressions
spontaneous combustion:
The occurrence of fire as a result of internal chemical processes without an external ignition source.
spontaneous decision:
A decision made quickly and without prior thought or consideration.
spontaneous reaction:
A chemical reaction that occurs without needing to be driven by an external source of energy.
Slang Meanings
Off the cuff
His off-the-cuff remarks were totally spontaneous and unfiltered.
On a whim
We went to the beach on a whim, it was a spontaneous decision.