Khom (Thai: ขอม, pronounced [kʰɔ̌ːm]) is a Thai- and Lao-language term referring to the people and civilization of the ancient Khmer Empire.
Its use is recorded as early as the 12th century, though its exact meaning—whether it refers to a specific empire, a certain historical period, or the Khmer people in general—has been unclear throughout history.
[1] The term has been used extensively in 20th-century Thai historiography, partly as a way to disassociate the historical Angkorian civilization—of which many archaeological sites are spread throughout present-day Thailand—from the present-day Khmer people who form the majority population of Cambodia, whom many Thais still believe to be an inferior race unrelated to the people of the ancient empire.
This discourse was popularized by 20th-century Thai nationalist thinker Luang Wichitwathakan who asserted that contemporary Khmers are unrelated to the ethnic group responsible for the Angkorian civilization, coining the term "khom" for this purpose.
[2][3] This is a commonly leveraged theme for anti-Khmer sentiment and historical negationism in Thai nationalist discourse.