Categorisation, also known as classification or grouping, is the process of arranging things or ideas according to their similarities and differences. Synonyms for categorisation include sorting, ordering, systematization, organization, and arrangement. These terms all suggest a systematic approach to categorizing something. Subdivision, segregation, and hierarchization are also related synonyms, indicating a more detailed or structured approach to categorization. Alternatively, bucketing, clustering, and tagging are synonyms that imply a more informal or experiential approach to categorization. Overall, choosing the right synonym for categorisation depends on the context and purpose of the categorization process.