Cure part of extreme dyslexia (6)
I believe the answer is:
remedy
'cure' is the definition.
('remedy' can be a synonym of 'cure')
'part of extreme dyslexia' is the wordplay.
'part of' indicates a hidden word.
'REMEDY' can be found hidden inside 'extreme dyslexia'.
(Other definitions for remedy that I've seen before include "'Cure, medicine (6)'" , "Medicine or therapy to cure" , "A treatment for disease" , "Put right, be a cure for" , "answer" .)