刻こっ苦く

noun, noun or participle which takes 'suru', intransitive verb

hard work; assiduous effort

Connotes strenuous, persevering effort, often in study or training. Commonly used in the phrase 刻苦勉励 (こっくべんれい).

• 彼かれは刻こっ苦く勉べん励れいして難なん関かん大だい学がくに合ごう格かくした。

  He passed the difficult university entrance exam through assiduous effort.

• 刻こっ苦くの末すえに、ついに新しん技ぎ術じゅつを開かい発はつした。

  After strenuous effort, they finally developed the new technology.