During my first year at the university, my very opinionated Western Civ. professor claimed that the 20th c. in Europe is called "the Age of Dehumanization." Is this actually an established periodization term, or is it something he himself made up?

I teach Western Civ quite a bit, and have used a number of different textbooks (Spielvogel; Cole & Symes; Perry; Hunt & Martin et al, etc.)

and I've never come across that periodization term.

Which does NOT mean that it's never been used...! Only that I myself have never seen it.

Far more common is the name popularized by Hobsbawm, the "Age of Extremes."

But I could see an intellectual argument for calling it the "Age of Dehumanization" (capitalism, consumerism, modernism fascism, totalitarian communism, racism, genocide) though the phrase seems a bit too clunky to catch on...