Definition of "subcategorization"

subcategorization

noun
countable and uncountable, plural subcategorizations
1. Placing something into a subcategory.
2. (grammar) The practice of specifying what types of complements a word may take when that word acts as the head of a phrase of a certain category; this specification restricts the wordʼs category, making it smaller, hence a “subcategory” of the wordʼs category.
  Quotations
  It seems a simple enough matter to extract a general principle of subcategorisation out of (81), along the lines of: (82) SUBCATEGORISATION PRINCIPLE (82) Any lexical item of category X will be subcategorised with respect (82) to the range of idiosyncratic Complements (i.e. sister constituents) (82) which it permits within the (minimal) X-bar containing it The subcategorisation frame for X will simply be an unordered list of the sets of categories which X permits as its Complements: we assume that the relative ordering of X and its Complements will be determined by independent principles (e.g. the HEAD FIRST PRINCIPLE).
  1988, Andrew Radford, chapter 7, in Transformational grammar: a first course, Cambridge, UK: Cambridge University Press, page 365