Reduplication

Webster's Dictionary of the English Language

·noun The act of doubling, or the state of being doubled.

II. Reduplication ·noun A figure in which the first word of a verse is the same as the last word of the preceding verse.

III. Reduplication ·noun The doubling of a stem or syllable (more or less modified), with the effect of changing the time expressed, intensifying the meaning, or making the word more imitative; also, the syllable thus added; as, ·Lat. tetuli; poposci.