This is the 8168th most frequent Japanese word.
山伏
A mountain ascetic monk.
In this sentence, '山伏' is used to denote a general reference to individuals associated with traditional ascetic practices.
山伏は昔の修行僧の一種です。
Yamabushi are a type of ancient monks who practiced asceticism.
Here, '山伏' refers specifically to the practitioners undergoing the training or practices.
山伏の修行は厳しい自然の中で行われます。
The training of yamabushi is conducted in harsh natural conditions.
In this case, '山伏' is used to illustrate the inspiration or model of behavior for the subject's actions.