subcategory

noun

1. With respect to a given category; a narrower category.

   “The moment subcategories of the overall population are denied rights, the rights of all are threatened.”

   “I have categories within subcategories because I get so many submissions about poop and potty training.”

   “On the other hand, the label of “feminist” is beginning to feel more like a subcategory on Netflix – an algorithmic signpost – than a meaningful description of art.”

2. A subclass of a category which is itself a category, whose arrows are a restriction of the arrows of the parent category, and whose composition rule is a restriction of the parent category's.