I’m not sure that it matters either way. I was castrated in 2015 but have never called myself a eunuch, even if that is what I am To the outside world am a man, even if not entirely so…

I prefer to call myself a castrated man

I saw the derivation of the word eunuch as bed guardian. (World Book dictionary).
Also if one looks up the prefix "eu-", it says "good, well, true"