Cultural genocide is a term that lawyer Raphael Lemkin

Raphael Lemkin

Raphael Lemkin was a Polish lawyer of Jewish descent. He is best known for his work against genocide, a word he coined in 1943 from the root words genos and -cide...

 proposed in 1933 as a component to genocide

Genocide

Genocide is defined as "the deliberate and systematic destruction, in whole or in part, of an ethnic, racial, religious, or national group", though what constitutes enough of a "part" to qualify as genocide has been subject to much debate by legal scholars...

. The term was considered in the 1948 United Nations Declaration on the Rights of Indigenous Peoples juxtaposed next to the term ethnocide, but it was removed in the final document, replaced with simply "genocide". The precise definition of "cultural genocide" remains unclear.
As early as 1933, lawyer Raphael Lemkin proposed a cultural component to genocide, which he called "vandalism

Vandalism

Vandalism is the behaviour attributed originally to the Vandals, by the Romans, in respect of culture: ruthless destruction or spoiling of anything beautiful or venerable...

".