忍俊 rěnjùn smiling Origin Definitions Defs Strokes Stroke Words Sentences Sents 忍俊不禁 rěnjùnbùjīn cannot help laughing To be unable to restrain a smile; to burst out laughing.忍俊不住 rěnjùnbùzhù cannot help laughing (variant form) to be unable to restrain a smile or to keep from laughing