
Ajahn (Thai:อาจารย์,RTGS: achan,IPA:[ʔāː.tɕāːn];Lao:ອາຈານ,romanized: ācān) is aThai- andLao-derived term that translates as "professor" or "teacher". The term is in turn derived from thePali wordācariya and is a term of respect, similar in meaning to the Japanesesensei. It is used as a title of address for high school and university teachers, and for Buddhist monks who have passed tenvassa – in other words those who have maintained their monastic precepts unbroken for a period of ten years. The termLuang Por, "Venerable father", signifies an ajahn of acknowledged seniority in Thai Buddhism.
According to theVinaya, any properly ordained monk can become anācariya after tenvassa in the robes, thus a Thai monk becomesajahn.
A senior monk may bear the honorific titlephra ajahn (Thai:พระอาจารย์,"venerable monk"), or in more informal situations,than ajahn (Thai:ท่านอาจารย์,"venerable monk").[1]
Some famousajahns are:
In Thai, such highly esteemed monks would rarely be called simplyajahn chah,ajahn mun, etc., as there are much more respectful ways for addressing or referring to them.
The term "Ajahn" is generally not formal enough to be used without the prefix "Pra" or "Tan" for monks when addressed by the laity, but this formality has been loosened when it comes to Western monks andTheravada monks well known outside Thailand.