A person with a high level of knowledge or skill, especially someone who is less able in other ways. (Cambridge Dictionary)
One with detailed knowledge in some specialised field (as of science or literature) (Merriam – Webster)
A person affected with a developmental disorder (such as autism or mental retardation) who exhibits exceptional skill or brilliance in some limited field (such as mathematics or music) (Merriam – Webster)
A savant is a person of great learning or natural ability. (Collins Dictionary)
What Makes an Autistic Person a Savant?
Acquired savant syndrome shows superhuman skills latent in anyone.