Which term refers to a mature male cat?

The term that refers to a mature male cat is "Tom." In the context of feline terminology, a "Tom" is specifically designated for intact (not neutered) male cats. Understanding this terminology is important for distinguishing between genders and breeding practices in animal husbandry.

The other terms provided relate to different species: "Doe" refers to a female deer or rabbit, "Stud" is a term commonly used for a male animal used for breeding, but it generally applies to horses or dogs rather than cats, and "Ewe" specifically refers to a female sheep. Thus, in the context of cats, "Tom" is the correct term to use for a mature male.