Change founder made is incredible (9,2)
I believe the answer is:
undreamed of
'incredible' is the definition.
(similar in meaning)
'change founder made' is the wordplay.
'change' is an anagram indicator.
'founder'+'made'='foundermade'
'foundermade' anagrammed gives 'UNDREAMED-OF'.
'is' acts as a link.
(Other definitions for undreamed of that I've seen before include "Transcending the fancy" , "Not previously thought possible" .)