the name for a castrated male cat is a gib.
A castrated male cat is usually just called a "neutered" or "fixed" male.
An entire (not neutered) male cat is called a Tom cat.
Tom is a boys name.
A male cat is NOT called a "cat." The proper name is "Tom." Thus, a female cat is called a "Queen."
Castration involves removing the testicles, since women have none to begin with a woman cannot be castrated.