Translation Japanese English: 艱険
Dictionary: main艱険形容詞3 arduous, 
 backbreaking, 
 grueling, 
 gruelling, 
 hard, 
 heavy, 
 laborious, 
 operose, 
 punishing, 
 straining, 
 strenuous, 
 toilsome. 
 4 arduous, 
 extreme, 
 extremist, 
 fierce, 
 radical, 
 straining, 
 strenuous, 
 tearing, 
 trigger-happy, 
 ultra, 
 utmost, 
 uttermost, 
 vehement, 
 violent.