Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
categorisation is a noun meaning "a group of people or things arranged by class or category". It carries 3 recorded senses.
a group of people or things arranged by class or category
the basic cognitive process of arranging into classes or categories
the act of distributing things into classes or categories of the same type
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for categorisation come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.