天てん然ねんに

adverb

naturally; spontaneously

Describes something happening without external force or artificial intervention, in a natural or spontaneous manner.

• 彼かれの才さい能のうは天てん然ねんに開かい花かした。

  His talent blossomed naturally.

• そのアイデアは天てん然ねんに浮うかんだ。

  The idea came to me spontaneously.