spontaneous (
http://definr.com/spontaneous)
adj 1: happening or arising without apparent external cause;
"spontaneous laughter"; "spontaneous combustion"; "a
spontaneous abortion" [syn:
self-generated] [ant:
induced]
2: said or done without having been planned or written in
advance; "he made a few ad-lib remarks" [syn:
ad-lib,
unwritten]
3: produced without being planted or without human labor; "wild
strawberries" [syn:
wild]