"-cide" is a suffix that means "to kill," as in:

  * suicide
  * regicide
  * fratricide
  * insecticide
  * pesticide

It comes from the Latin word "caedo," which means "to kill." The phrase "cultural genocide" is not the same as "genocide," and indeed the legal definition of "genocide" expliticly says that destruction of a culture is not genocide.

Using the word "genocide" to refer to something other than mass murder - and then falling back to the claim that "genocide" doesn't mean mass murder - is just playing rhetorical games.