Definition of "senex"

6. Old Men or Senexes. Frequently these characters have a beautiful young ward who, often, they wish to marry (or wish to marry off to someone the ward doesn’t like) and it is the task of the hero, the male lead, often helped by a shrewd servant or slave (or similar figure) to outwit the senex and marry the girl. Sometimes the senex figure is actually married to a young wife and that poses numerous complications: the old husband is jealous, the young wife unsatisfied in various ways with a different perspective on life.

1997, Arthur Asa Berger, The Art of Comedy Writing, published 2017

Now for more about the four birds, explicitly identified with the four evangelists as the four old men or Senexes. Notice the repetition on four as the four Gospel books repeat much of the same history of Christ, perhaps as a result of an editorial effort to achieve uniformity.

2013, John P. Anderson, Joyce’s Finnegans Wake: The Curse of Kabbalah, volume 7, Universal Publishers, page 53

It concludes, though, not with an image of resigned heads or rebellious newcomers: instead, after the camera lifts for the final credits to the heavens—the only site for the senexes’ social and educational ideals?—it descends on the playing fields where the school’s ration-book-resourceful porter Rainbow (Edward Rigby) and his youthful assistant are seen collapsed under the frequently-removed rugby posts.

2016, Stephen Glynn, The British School Film: From Tom Brown to Harry Potter, Palgrave Macmillan, page 90