プログレッシブ和英中辞典(第4版)の解説
くしん【苦心】
pains（▼常に複数形）；hard work
苦心する take pains; work hard
苦心してそれを調べあげた
「He went to great pains [He put in a lot of hard work] investigating it.
この本は彼の苦心が実ったものである
This book of his is the fruit of 「much labor [a lot of hard work].
せっかくの苦心も水の泡になった
All his efforts came to nothing.
難問を解こうと苦心している
He is cudgeling [racking] his brains trying to solve a difficult problem.
この筆使いに苦心の跡が見られる
There are traces of painstaking effort in this brushwork.
この辞書は大勢の人の苦心の作である
This dictionary is the result of a lot of hard work on the part of many people.
苦心惨憺(さんたん)
この金を工面するのに苦心さんたんした
I went to a lot of trouble to raise this money.／I had a hard time raising this money.
苦心談
それを発明するまでの苦心談を語った
He spoke about the difficulties he experienced inventing it.