A child prodigy is defined in psychology research literature as a person under the age of ten who produces meaningful output in some domain to the level of an adult expert.

The term wunderkind (from German Wunderkind; literally "wonder child") is sometimes used as a synonym for child prodigy, particularly in media accounts. Wunderkind also is used to recognize those who achieve success and acclaim early in their adult careers.

 

Note:   The above text is excerpted from the Wikipedia article Child prodigy, which has been released under the GNU Free Documentation License.