Responses

it can't be translated wrong because eunuch isn't english to begin with. I think his friends called him that mostly to give him a hard time.

Oh! My bad. I just found out it is in english I just never seen it before. It means someone who is castrated. Still, I don't think they mean it in the literal sense.
I think the translators have it a bit wrong. Eunuch is the guy that he has his balls cut. Jae jin is impotent. Is it so hard to know the difference? ლ(´ڡ`ლ)