nouns - Is there a word similar to "racism" when referring to an ethnic group rather than a race?

I called out someone's comments as racist when someone decided to correct me and say that the term was incorrect. According to this person, the word racism only seems to apply when referring to another race (e.g. Sub-Saharan African, White European, East-Asian, South-Asian, Native American, etc.)

What is the similar term then for hatred towards a particular ethnic group? (E.g. Italian, Serbian, Sri Lankan, etc.)

Answer

Racism can have many definitions and depends on the definition of race you're using. Here's several definitions from dictionary.com:

race2    [reys]

1. 
   

   a group of persons related by common descent or heredity.

   
   


2. 
   

   a population so related.

   
   


3. 
   

   Anthropology.
   a. any of the traditional divisions of humankind, the commonest being the Caucasian, Mongoloid, and Negro, characterized by supposedly distinctive and universal physical characteristics: no longer in technical use.
   b. an arbitrary classification of modern humans, sometimes, especially formerly, based on any or a combination of various physical characteristics, as skin color, facial form, or eye shape, and now frequently based on such genetic markers as blood groups.
   c. a human population partially isolated reproductively from other populations, whose members share a greater degree of physical and genetic similarity with one another than with other humans.

   
   


4. 
   

   a group of tribes or peoples forming an ethnic stock: the Slavic race.

   
   


5. 
   

   any people united by common history, language, cultural traits, etc.: the Dutch race.

   
   

As you can see, one of these can be segregation by skin colour, another can be by ethnic group, so you can use racism.

More generally, racism is a form of prejudice, hate or intolerance, so you could use any of those words. If it's hatred against foreigners in general, you can use xenophobia.