noun
ethnologist
A scholar who studies ethnic groups, their cultures, and social structures.
彼女はアフリカの部族を研究する民族学者です。
She is an ethnologist who studies African tribes.
文化人類学者 (cultural anthropologist) is a broader term often used interchangeably, but 民族学者 may emphasize the study of specific ethnic groups and their traditions.
Compound of 民族 (ethnic group) + 学 (study) + 者 (person).