Pir or Peer is a title for a Sufi master equally used in the nath

Nath

The Sanskrit word nāthá or नाथ, is the proper name of a Hindu initiatory tradition and the word itself literally means "lord, protector, refuge"...

 tradition. They are also referred to as a Hazrat or Shaikh, which is Arabic for Old Man. The title is often translated into English as "saint" and could be interpreted as "Elder

Elder (Christianity)

An elder in Christianity is a person valued for his wisdom who accordingly holds a particular position of responsibility in a Christian group. In some Christian traditions an elder is a clergy person who usually serves a local church or churches and who has been ordained to a ministry of Word,...

". In Sufism

Sufism

Sufism or ' is defined by its adherents as the inner, mystical dimension of Islam. A practitioner of this tradition is generally known as a '...

 a Pir's role is to guide and instruct his disciples on the Sufi path. This is often done by general lessons (called Suhbas) and individual guidance. Other words that refer to a Pir include, Murshid

Murshid

Murshid is Arabic for "guide" or "teacher". Particularly in Sufism it refers to a Sufi teacher. The term is used by other branches of Islam as well, e.g. by the Nizaris, the main school of Ismā‘īlī Shiites....

, Sheikh

Sheikh

Not to be confused with sikhSheikh — also spelled Sheik or Shaikh, or transliterated as Shaykh — is an honorific in the Arabic language that literally means "elder" and carries the meaning "leader and/or governor"...

and Sarkar (Persian/Hindi/Urdu word meaning Master, Lord).

The path of Sufism starts when a student takes an oath of allegiance with a teacher called Bai'ath or Bay'ah

Bay'ah

Bay'ah , in Islamic terminology, is an oath of allegiance to a leader. It is known to have been practiced by the Islamic prophet Muhammad...

(Arabic word meaning Transaction). After that, the student is called a Murid

Murid

Murid is a Sufi term meaning 'committed one' from the root meaning "willpower" or "self-esteem". It refers to a person who is committed to a Murshid in a Tariqa of Sufism. Also known as a Salik , a murid is an initiate into the mystic philosophy of Sufism. When the Talib makes a pledge to a...

 (Arabic word meaning committed one).

A Pir usually has authorizations to be a teacher for one (or more) Tariqah

Tariqah

A tariqa is an Islamic religious order. In Sufism one starts with Islamic law, the exoteric or mundane practice of Islam and then is initiated onto the mystical path of a tariqa. Through spiritual practices and guidance of a tariqa the aspirant seeks ḥaqīqah - ultimate truth.-Meaning:A tariqa is a...

s (paths). A Tariqah may have more than one Pir at a time. A Pir is accorded that status by his Shaikh by way of Khilafat or Khilafah (Arabic word meaning succession). Khilafat is the process in which a Shaikh identifies one of his disciples as his successor (khalifah

Caliph

The Caliph is the head of state in a Caliphate, and the title for the ruler of the Islamic Ummah, an Islamic community ruled by the Shari'ah. It is a transcribed version of the Arabic word   which means "successor" or "representative"...

). A Pir can have more than one khalifah.