Definition - The process of creating a new word by repeating a part of an existing word.

Example -
boogie-woogie, chit-chat, and baby-shmaby.

Etymology -
The word derives from the Latin reduplicare, to redouble (from re, again + duplicare, to double).
Note: The language term reduplication is a misnomer because the phenomenon usually involves doubling not redoubling.

Oxford English Dictionary -
Its first citation in this sense is from 1862:
"They are traceable in many reduplications, and influence the choice of vowel-sounds in a large class of words."
(D. Wilson Preh. Man iv. (1865) 65)

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