spontaneous

UK: spɒnˈteɪniəs | US: spɑːnˈteɪniəs

Definition

  1. adj. occurring or produced without external cause or planning; natural

  2. adj. arising from internal impulses; unforced

  3. adj. (biology) growing or developing without external stimuli

Structure
spont <of one's own will>aneous <adjective suffix>spont <of one's own will>aneous <adjective suffix>
Etymology

The word traces back to Latin spontaneus, which emphasized actions arising from free will rather than external coercion. Over time, it evolved in English to describe natural, unplanned occurrences (e.g., laughter, reactions) and later extended to biological processes (e.g., growth). The core idea—self-originating action—remains central.

Examples

  1. Her spontaneous laughter brightened the room.

  2. The crowd erupted in spontaneous applause.

  3. He made a spontaneous decision to travel abroad.

  4. Some plants exhibit spontaneous movement in response to light.

  5. Their spontaneous road trip became the highlight of their summer.