Both changed Edward in nursery (6)
I believe the answer is:
hotbed
'nursery' is the definition.
(thesaurus)
'both changed edward' is the wordplay.
'changed' indicates anagramming the letters.
'edward' becomes 'Ed' (short for Edward).
'both' with letters rearranged gives 'hotb'.
'hotb'+'ed'='HOTBED'
'in' is the link.
(Other definitions for hotbed that I've seen before include "Forced to grow up early in this" , "vicious place" , "Place with ideal conditions for rapid growth" , "breeding-ground for problems" , "Scene of rapid growth, as of intrigue" .)