Denshi Jisho — Online Japanese dictionary

突然 とつぜん abrupt; sudden; unexpected; all at once
Common word, Na-adjective, No-adjective, Adverb 
突然死 とつぜんし sudden death
Noun 
突然目 とつぜんめ somewhat sudden
Expression 
突然変異 とつぜんへんい mutation
Noun 
突然だけど とつぜんだけど apropos of nothing; to change the subject
Expression 
突然変異説 とつぜんへんいせつ mutationism
Noun 
突然変異体 とつぜんへんいたい mutant
Noun 

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