Greek character from university returning cured of speech impediment? (7)
I believe the answer is:
upsilon
'greek character' is the definition.
(letter from the Greek alphabet)
'university returning cured of speech impediment?' is the wordplay.
'university' becomes 'u' (abbreviation for university).
'returning' shows that the letters should be reversed in order.
'cured of speech impediment?' becomes 'nolisp' (lisp is a type of speech impediment).
'nolisp' in reverse letter order is 'psilon'.
'u'+'psilon'='UPSILON'
'from' acts as a link.
(Other definitions for upsilon that I've seen before include "Greek 'u'" , "Greek letter" , "Greek character" , "Character from abroad" .)