This article argues that the defamiliarization caused by extensive repetition, termed ‘semantic satiation’ in psychology, was used by ancient poets for specific effects. Five categories of repetition are identified. First, words undergo auditory deformation through syllable and sound repetition, as commonly in ancient etymologies. Second, a tradition of emphatic proper-name repetition is identified, in which the final instance of the name is given special emphasis; this tradition spans Greek and Latin poetry, and ultimately goes back to the Nireus entry in the Catalogue of Ships. Third, repetition is used for wordplay, where the final instance of the repeated term not only is emphasized but also incurs some change to its meaning or shape. Fourth, the incantatory repetition of divine names in hymns and cultic invocations amplifies a sense of divine presence behind and beyond the repetend. Fifth, repetition of half and full lines by different speakers in Old Comedy serves to undercut and parody the original sense of the repeated words. Extensive repetition in ancient literature was never merely ornamental but was used for a range of specific auditory and semantic effects with distinct and identifiable structures.