( a. )
Proceeding from, or acting by, internal impulse, energy, or natural law, without external force; as, spontaneous motion; spontaneous growth.
( a. )
Proceeding from, or acting by, internal impulse, energy, or natural law, without external force; as, spontaneous motion; spontaneous growth.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012