Correct me if I'm wrong I think Misha Mansoor (Periphery) coined the name Djent to describe a guitar tone he was trying to achieve.
As with all language words gain and lose meaning but as it stands I think Djent is a genre. When people say Djent I think of bands like Periphery, Monuments, Sikth and Meshuggah. Regardless of the origin of the word it seems to have stuck with the metal community. At least for now.