Is there a definition for someone who is retarded, but smart.?

‘Idiot Savant’ is the term used for a person, often but not always autistic, who has genius abilities in on particular area, often mathematics. Remember Dustin Hoffman as ‘Rainman’? He was an idiot savant.

Auto Savant

A good example in popular culture was the movie “The Rainman” starring Dustin Hoffman and Tom Cruise – A very good movie.

Remarkably some of these people are retarded in some areas, but at the same time able to do some incredible things, such a complex mathematical computations mentally, or incredible memories ( Surprisingly though often for only certain things in particular)

Truly remarkable people!

In reply to your additional details:

You can call her the “Dumbest smart person you know”

Or the “Smartest Dumb person you know”

Depends on how nice you are feeling on the day : -)

You are a complete Boffin

This is for someone very smart to the exclusion of all other social skills (c;

underachiever-someone who performs below what would expected on the basis of abilities.* These abilities can be most apparent so it is often surprising when underachievement occurs.

*possibly indicated by intelligence tests.

ima hopeless retarded fool

a savant

“idiot savant” – This is oprobably the term you are looking for.