Spontaneous

Definition of Spontaneous
Adjective

1. spontaneous, self-generated (happening or arising without apparent external cause) "spontaneous laughter"; "spontaneous combustion"; "a spontaneous abortion"

2. ad-lib, spontaneous, unwritten (said or done without having been planned or written in advance) "he made a few ad-lib remarks"

Adverbs for Spontaneous
eagerly; obviously; enthusiastically; utterly; manifestly; remarkably; absolutely; palpably; unquestionably; warmly; fervently: heartily; undoubtedly; intensely; exceptionally; sympathetically; unusually.