What is a wandering Hindu ascetic holy man called?

The correct term for a wandering Hindu ascetic holy man is "Sadhu." Sadhus are individuals who have renounced worldly pursuits and live a life of meditation and spiritual practice, often traveling and living a simple, ascetic lifestyle devoted to their spiritual beliefs. They are typically seen as holy men and are often revered in Hindu culture.

The term "Sannyasin" refers to someone who has chosen to take on the fourth and final stage of life in Hindu philosophy, which emphasizes renunciation. While a Sannyasin may engage in similar practices to a Sadhu, the term specifically describes one who has formally entered this stage of life rather than just referring to any wandering ascetic.

A "Guru" is a spiritual teacher or guide in Hinduism who imparts knowledge and wisdom to students, often but not exclusively associated with the destinies of Sadhus and Sannyasins.

"Brahman," on the other hand, is a concept in Hinduism that refers to the ultimate reality or cosmic spirit, not a term for a holy man.

Understanding the distinctions among these terms can clarify the nuanced roles and meanings within Hinduism, highlighting why "Sadhu" is the appropriate answer in this context.