idiolect

This term is primarily used in linguistics and forensic linguistics to describe the linguistic fingerprint of a person. It encompasses every idiosyncratic habit of speech, from preferred adjectives and rhythmic patterns to specific mispronunciations or regional slang that a person has internalized over time.

While a dialect is shared by a community, an idiolect is strictly individual. In legal contexts, analyzing an idiolect allows experts to identify authorship of anonymous texts by spotting recurring patterns that are unique to one specific writer, distinguishing it from the broader sociolect of a social class or the regional dialect of a geographic area.