'autoplagiarism' originates from a combination of the Greek prefix 'auto-' (from Greek 'autos', meaning 'self') and the noun 'plagiarism' (from Latin 'plagiarius'), where 'auto-' meant 'self' and 'plagiarius' referred to a 'kidnapper' or one who steals.

'plagiarism' comes from Latin 'plagiarius' meaning 'kidnapper'; it entered English via Late Latin/Medieval usage as 'plagiary' and developed into the modern English word 'plagiarism'. The modern compound 'autoplagiarism' arose in recent academic English by prefixing 'auto-' to 'plagiarism' to specify 'self-' theft of one's own work.

Initially, the Latin root referred to physical 'kidnapping' or abduction; over time the term shifted metaphorically to mean 'stealing another's literary work' and now is extended in compounds like 'autoplagiarism' to mean inappropriate reuse of one's own work.