I would say I have more than just a passing interest in the academic study of Western Esotericism. I count among my friends several authors who have published important contributions to the formal study of this newer area of academia. I am one of the founding organizers of the Esotericism in Freemasonry Conference. I frequently talk about Western Esotericism so you would think I have some idea of what it might be.
Turns out, when asked to "define" this field of study on a recent podcast interview, I was woefully underprepared. This wiki article does an excellent job of defining the broad strokes of the definition and how many areas are still being developed and defined. https://en.wikipedia.org/wiki/Western_esotericism
Consider this missive a promise to you, my "listener", to get at least a passing familiarity with the four major and two minor factors used for identification of "Western Esotericism". I am sure the late Antoine Faivre would be proud. Too bad I had to let Pat and Jake at Tria Prima Podcast down to realize what I didn't know I didn't know.