A group, often named or numbered, to which items are assigned based on similarity or defined criteria.

plural of category

categorical, absolute, without exception / categorical, pertaining to a category / pertaining to categorial grammar

In a categorial manner.

Alternative spelling of subcategory

plural of category killer

(business, US) A retailer that offers a wider selection of merchandise in a category than existing retailers, at lower prices, thereby gaining substantial share of the market and "killing" the existing retailers.

(mathematics) A branch of mathematics which deals with spaces and maps between them in abstraction, taking similar theorems from various disparate more concrete branches of mathematics and unifying them.

(linguistics) A linguistic category of words (or more precisely lexical items), generally defined by the syntactic or morphological behaviour of the lexical item in question, such as noun or verb.

A semantic or ontological error by which a property is ascribed to a thing that could not possibly have that property.