たくましくする

suru verb (special), transitive verb

give free rein to (imagination); let one's imagination run wild

Used specifically with 想像力 (imagination) to mean allowing it to work freely and vividly. Often appears in the phrase 想像力を逞しくする.

• 子こ供どもの頃ころは、よく想そう像ぞう力りょくを逞たくましくして遊あそんだものだ。

  When I was a child, I used to play while giving free rein to my imagination.

• 彼かれは想そう像ぞう力りょくを逞たくましくして物もの語がたりを作つくった。

  He let his imagination run wild and created a story.