勉べん強きょう不ぶ足そく

noun

insufficient study; lack of preparation

Used when someone has not studied enough, often as a self-deprecating or critical remark about one's own or another's knowledge.

• 試し験けんに落おちたのは勉べん強きょう不ぶ足そくのせいだ。

  Failing the exam was due to insufficient study.

• 彼かれの説せつ明めいが下手へたなのは、単たんに勉べん強きょう不ぶ足そくだ。

  His poor explanation is simply a lack of preparation.