How would you describe something that is "spontaneous"?

Describing something as "spontaneous" refers to actions or events that occur naturally and without prior planning or deliberation. The term captures the essence of a sudden or impromptu occurrence, emphasizing the lack of premeditation or structure. This aligns perfectly with the idea of something being unplanned, reflecting an organic flow rather than a calculated approach.

In contrast, the other descriptions focus on order, rarity, or planning. For instance, "carefully planned" signifies a meticulous approach that is the opposite of spontaneity. "Occasional and rare" implies infrequency, which doesn’t necessarily relate to the unrestrained nature of spontaneous actions. Likewise, "uniform and consistent" suggests predictability and stability, which contrasts with the unpredictable and dynamic essence of spontaneity. Thus, the choice that accurately encapsulates the meaning of "spontaneous" is, indeed, unplanned and natural.