なんこうふらく 難攻不落 LinksSentence search for 難攻不落Sentence search for なんこうふらくKanji details for 難, 攻, 不 and 落Edit in JMdict Noun, Noun which may take the genitive case particle 'no'1. impregnableYojijukugo (four character compound) Discussions Log in to talk about this word.