for questions pertaining to "a morphological process in which the root or stem of a word (or part of it) or even the whole word is repeated exactly or with a slight change."

The repetition of phonological material within a word for semantic or grammatical purposes is known as reduplication, a widely used morphological device in a number of the world’s languages. The languages classified on the accompanying map are sorted into three categories: languages that do not employ reduplication as a grammatical device, languages that productively employ both partial and full reduplication, and languages that only employ full reduplication.

More info here @WALS and here @Wikipedia.