Luang por (Thai: หลวงพ่อ; RTGS: luang pho, Thai pronunciation: [lǔəŋpʰɔ̂ː]; Lao: ຫຼວງ ພໍ່, romanized: lūang phǭ) means "venerable father" and is used as a title for respected senior Buddhist monastics.
For instance, Luang Por Ajahn Chah was a well-known and widely respected monk.
In his middle and older years as respect for him grew, people sometimes referred to him simply as "Luang Por".
The system is Vague and is a reflection of the method of respect used in everyday Cotidian life in Thailand, where age means status, and the classification of the terminology used for different Family relatives is doubly complex as that Western system.
The one exception is the word "Nong" (meaning younger brother or sister) which is never used by a layperson to a Monk, only older terms are used.