ascetic monk; trainee monk
A Buddhist monk engaged in rigorous spiritual training, often involving meditation, austerity, and physical discipline.
The ascetic monk wakes up early every morning and practices zazen.
He entered the temple as a young trainee monk.
修行者 is a broader term for anyone engaged in spiritual or martial training, not limited to Buddhist monks.
Compound of 修行 (shugyō, 'ascetic training') and 僧 (sō, 'monk').