reduplicate

Concise Oxford English Dictionary © 2008 Oxford University Press:
reduplicate/riːˈdjuːplɪkeɪt/

▶verb

• 1 repeat or copy so as to form another of the same kind.

• 2 repeat (a linguistic element) exactly or with a slight change (e.g. hurly-burly).

– derivatives
reduplication noun,
reduplicative adjective.

– origin C16 (earlier (ME) as reduplication): from late L. reduplicat-, reduplicare ‘double again’, from re- ‘again’ + duplicare (see duplicate).