"Apo" (greek base): Prefix occurring originally in loanwords from Greek, where it was joined to verbs, deverbal forms,and other parts of speech. Among its functions in Greek, apo- has the spatial sense “away, off,apart” ( apogee; apocope; apostasy; apostrophe ); it occurs with deverbals that denote a responseor defense ( apodosis; apology ) and is found on verbs having perfective force relative to a corresponding simple verb ( apoplexy; aposiopesis ). In modern scientific coinages in English andother languages, apo- marks things that are detached, separate, or derivative ( apocarpous;apoenzyme ).
"Andra" (greek base): From Ancient Greek ἀνδρός (andrós), genitive of ἀνήρ (anḗr, “man, husband”).
"Sis" (greek base): -sis. suffix in Greek-derived nouns denoting action, process, state, condition, fromGreek -sis , which is identical in meaning with Latin -entia , English -ing (1).
Looking at this word, I am assuming the basis has something to do with fighting ships (and bureaucracies) being crewed (staffed) exclusively by men as of Sept 1, 1939 and something, an irregularity, became manifest that was different than the crew (staff) at that moment...and undeniably feminine and therefore "not man". As of a week and a half into the Morgana events, so little is known about what the heck is happening, add the natural desire to cling to some scientific basis for what is otherwise pure madness, official discourse hearkens back to Greek for sanity. So the Belles, a term which would not have become colloquial yet, are clearly NOT men (apoandra) yet came into being (sis). Once the term was coined, I could see it remaining in use for official purposes by bureaucrats fiercely resisting placing fairy tales in their precious documents.
In a less patriarchal world, I would like to think "apoanthroposis" would have been the choice, but in a world led, staffed and crewed by men, I can understand the inherently sexist choice. Fortunately the Belles themselves will hasten a revolution that has already been fulminating during the interwar years. Thanks to the Morganas and Belles, an "anthropo" rather than an "andra" world is manifesting. 🙂
I'll add that the term "apoandrasis" opens up "not husband" as a parallel interpretation which would suggest the possibility for "wife". Again, sexist as hell but opens up that MEN were already thinking of Belles in terms of waifu material even in the initial days... 😛