-
adjective
happening or arising without apparent external cause
"spontaneous laughter"
"spontaneous combustion"
"a spontaneous abortion"
-
adjective
said or done without having been planned or written in advance
-
intuitive
spontaneously derived from or prompted by a natural tendency
-
autotomy
spontaneous removal or casting off of a body part (as the tail of a lizard or claw of a lobster) especially when the organism is injured or under attack