'Dickens' originates from Middle English, specifically the diminutive name 'Dicken' (from 'Dick'), where 'Dick' was a pet form of 'Richard' and the suffix '-en/-kin' indicated a diminutive.

'Dicken' (a diminutive of 'Dick') changed into the hereditary surname 'Dickens' in later Middle English; the possessive form 'Dickens's' is formed by adding the English genitive 's.

Initially it indicated a diminutive or descendant of 'Dick' (i.e., 'little Dick' or 'son/descendant of Dick'), and over time it became a fixed family name; the possessive simply denotes belonging or association.