The Merriam-Webster word of the day is Savant.

Noun: sa-VAHNT

Definition

1: a person of learning; especially: one with detailed knowledge in some specialized field (as of science or literature)

2: a person affected with a mental disability (such as autism) who exhibits exceptional skill or brilliance in some limited field (such as mathematics or music); especially: autistic savant

Example:

“His conversation, I remember, was about the Bertillon system of measurements, and he expressed his enthusiastic admiration of the French savant." — Sir Arthur Conan Doyle, The Memoirs of Sherlock Holmes, 1893

According to Merriam Webster:

“Savant comes from Latin sapere- “to be wise”- by way of Middle French, where savant is the present participle of savoir, meaning “to know”.

“Savant shares roots with the English words sapient- “possessing great wisdom”- and sage -“having or showing wisdom through reflection and experience”.

“The term is sometimes used in common parlance to refer to a person who demonstrates extraordinary knowledge in a particular subject, or an extraordinary ability to perform a particular task, such as complex arithmetic, but who has much more limited capacities in other areas.