spontaneously

Later, as he digs into the making and meaning of his movie, he’ll relax and the words will spontaneously flow.

Either the liver ruptured because of a needle or it ruptured spontaneously.

It's still not clear why the outbreak spontaneously ceased and it hasn't resurged over the past decade.

In contrast, auto-focus lenses promise to adjust part or all of the lens spontaneously, and even accommodate the wearer's changing eyesight over time.

He said the community gathered "spontaneously and collectively" in the gardens outside The Atkinson, "standing defiantly in the face of evil".