Ajahn (Thai: อาจารย์, RTGS: achan, also romanized ajaan, ajarn, acharn and achaan) is a Thai language term which translates as "teacher". It is derived from the Pali word ācariya, and is a term of respect, similar in meaning to the Japanese sensei, and is used as a title of address for high-school and university teachers, and for Buddhist monks who have passed ten vassa.

This lattermost case is usually romanized ajahn. According to the Vinaya, any properly ordained monk can become an ācariya after ten vassa in the robes, thus a Thai monk becomes ajahn.

A senior monk may bear the honorific title phra ajahn (Thai: พระอาจารย์,"venerable monk"), or in more informal situations, than ajahn (Thai: ท่านอาจารย์,"venerable monk").

Some famous ajahns are:

  • Ajahn Amaro
  • Ajahn Maha Boowa
  • Ajahn Brahm
  • Ajahn Chah
  • Ajahn Khemadhammo
  • Ajahn Mun
  • Ajahn Munindo
  • Ajahn Sumedho

In Thai, such highly esteemed monks would very rarely be called simply ajahn chah, ajahn mun, etc., as there are much more respectful ways for addressing or referring to them.

Other articles related to "ajahn":

... Theravada Buddhist monastery in the Thai Forest Tradition lineage of Ajahn Chah located near Rome ... In the Spring of 1990 the former Italian Bhikkhu Ajahn Thannavaro and then Anagarika John Angelori were sent by Ajahn Sumedho to take up residence in ... Ajahn Chandapalo was invited to become the new abbot, a position he has held to the present day ...
Aruna Ratanagiri - History
... in northeast England, in the Thai Forest Tradition, as it was being established by Ajahn Sumedho and disciples of Ajahn Chah in England in the late 1970s ... In 1981 Ajahn Sucitto (now the abbot of Cittaviveka/Chithurst Buddhist Monastery) became the first bhikkhu to take up residence, and began initial renovations on June 21, 1981 ...
Aruna Ratanagiri - See Also
... Thai Forest Tradition Ajahn Chah Ajahn Sucitto Ajahn Amaro Amaravati Buddhist Monastery, UK Chithurst Buddhist Monastery, UK Wat Nong Pah Pong, Thailand Wat Pah Nanachat, Thailand ...
Ajahn Sao Kantasilo Mahathera
... Phra Ajahn Sao Kantasilo Mahathera (1861–1941) was a monk in the Thai Forest Tradition of Theravadin Buddhism ... Ajahn Mun Bhuridatta Mahathera was one of his most well-known students ... Once-returner Non-returner Arhat Monasticism Monk Nun Novice monk Novice nun Anagarika Ajahn Sayadaw Zen master Rōshi Lama Rinpoche Geshe Tulku ...
Ajahn Amaro - Biography - Origins of California's Abhayagiri Monastery
... Since for some years Ajahn Sumedho had venerated the Chinese master, both abbots hoped that, among its other virtues, the center would serve as a ... Ajahn Pasanno was appointed founding co-abbot of Abhayagiri with Ajahn Amaro ... would be leaving Abhayagiri and returning to England, having accepted a request from Ajahn Sumedho to succeed him as abbot at Amaravati ...