(1) Said or done without having been planned or written in advance
"He made a few ad-lib remarks"
(2) Happening or arising without apparent external cause
"A spontaneous abortion"
, from .
- Self generated; happening without any apparent external cause.
- He made a spontaneous offer of help.
- Done by one's own free choice, or without planning.
- proceeding from natural feeling or native tendency without external constraint
- arising from a momentary impulse
- controlled and directed internally : self-active : spontaneous movement characteristic of living things
- produced without being planted or without human labor : indigenous
- not apparently contrived or manipulated : natural
- Sudden, without warning.