the action or process of reiterating, repeating, doubling something;
e.g. I was busy with the reduplication of some old paintings.
(noun)
a phenomenon in linguistics in which a word, phrase, or some other grammatical element is repeated, sometimes with some minor change, in a way that is meaningful, or a word or repeated segment in such a usage;
e.g. He studied the origin of phrases that used reduplication and how these arose.