ラーオ語
Isan people have traditionally referred to their speech as "Phasa Lao" (, /pʰáː săː láːw/) or 'Lao language'. This is sometimes modified with the word "tai" (, , /tʰáj/), which signifies an 'inhabitant' or 'people', or the related form "Thai" (, , /tʰáj/), which refers to Thailand or the Thai people, thus yielding "Phasa Tai Lao" (, ), 'language of the Lao people' and "Phasa Thai Lao" (, ), 'Lao language of Thailand'. "Lao" derives from an ancient Austroasiatic loan into Kra-Dai, *"k.ra:w", which signified a '(venerable) person' and is also ultimately the source of the Isan words "lao" (, , /láːw/), 'he'/'she'/'it', and "hao" (, , /háo/), 'we'. "Tai" and "Thai" both derive from another Austroasiatic loan into Kra-Dai, *"k.riː", which signifies a '(free) person'. The various Kra-Dai peoples have traditionally used variants of either *"k.riː" or *"k.ra:w" as ethnic and linguistic self-appellations, sometimes even interchangeably.