savant

Short definition from Wiktionary

Noun

1. 1
   A person of learning, especially one who is versed in literature or science.
2. 2
   A person who is considered eminent because of their achievements.
3. 3
   A person with or without significant mental disabilities who is very gifted in one area of activity, such as playing the piano or mental arithmetic.

Proper noun

1. 1
   A surname.