自し然ぜん発はっ火かMeaningsNoun1. spontaneous combustionKanji used自self然sort of thing発let out火firePitch accentしぜんはっかComposed of自し然ぜんnature; natural; spontaneous; automatic; naturally; spontaneously; automaticallyNoun発はっ火かignition; combustion; catching fire; firing a blank cartridge; discharge of a gun without bullets; firing (of an event); triggeringNoun