Last name เทศน์ (Thet 
, Sermbhat , เทศน์ ) , globally, is a widespread family name. The surname เทศน์ is characteristic of Mongolia, where it is a prevalent surname, Myanmar, where it is a widespread surname, and Singapore, where it is quite a rare surname. Measured by absolute frequency, this name is the most popular in Myanmar, Mongolia, and Malaysia. Also, เทศน์ is the forename as well as the last name.