To search for or seek something, often with determination or over a long period.
彼は失われた故郷を生涯探し求めた。
He spent his life searching for his lost hometown.
多くの人が本当の幸せを探し求めている。
Many people are seeking true happiness.
必要な資料を図書館で探し求めた。
I searched the library for the necessary materials.