I have not (yet) studied Ancient Greek. This comment introduced me to the pertinence of Aristotle's Prior Analytics, but a translation below does not resolve my question entitled above.
Source: Aristotle's Prior Analytics: Book I, Translated with an introduction and commentary (2009) by Gisela Striker
[page 4, Chapter 4, 25b, Lines 35-36]
Extremes are what is in another and that in which there is another.
[page 95] 25b35-37 [...] As a terminological introduction this is a little confusing, and so the ancient commentators simply replace Aristotle's explanations by the later definitions that hold for all three figures : the middle term is the one that occurs in both premisses, the extremes are the terms of the conclusion, with the predicate term being the greater (major), the subject term the smaller (minor) . Again, the labels 'major' and 'minor' are presumably taken from the example of Barbara (see below, 26a 21-3 ). One must admit that Aristotle's choice of labels is unfortunate and possibly misleading, but it has served its purpose well enough through the ages, and it obviously did not mislead Aristotle himself.