Late Latin spontāneus.
- Self-generated; happening without any apparent external cause.
- Done by one’s own free choice, or without planning.
- Proceeding from natural feeling or native tendency without external or conscious constraint.
- Arising from a momentary impulse.
- Controlled and directed internally; self-active; spontaneous movement characteristic of living things.
- Produced without being planted or without human cultivation or labor.
- Random.
- Sudden, without warning.