Synonyms of spontaneous

Adjective

1. spontaneous (vs. induced), self-generated, impulsive, unprompted, intuitive, natural, instinctive

usage: happening or arising without apparent external cause; "spontaneous laughter"; "spontaneous combustion"; "a spontaneous abortion"

2. ad-lib, spontaneous, unwritten, unscripted (vs. scripted)

usage: said or done without having been planned or written in advance; "he made a few ad-lib remarks"

Definition and meaning of spontaneous (Dictionary)