The most shameless or prolific person who steals others' writing or ideas and passes them off as their own.
Arch- plus plagiarist (from Latin plagiarius, kidnapper, evolved to mean literary thief). The compound emerged in Early Modern English as critics needed to describe the worst offenders in academic and literary circles.
During the Renaissance, writers battled each other with these compound insults—calling someone an 'archplagiarist' was basically a scholarly roast suggesting they had no original thoughts whatsoever.
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