Actually KillBelle. An Orchi, or Orchidectomy, is the medical term for the removal of the testes. So Castration could be used. So could neutered, or fixed. But the term Orchi is generally use as it is a shortened version of the proper procedure.
And you did not seem ignorant. I have always said the only dumb question is the one not asked. You did not know, although you were in the right area, so you asked, and now you know.
Endocrinologically, the hormones, I am the same as any post-op. The only different is the genitalia. I still have a penis.