French editor celebrated, ultimately fantastic editor (7)
I believe the answer is:
diderot
'french editor' is the definition.
The definition suggests a singular noun which matches the answer.
'celebrated ultimately fantastic editor' is the wordplay.
'ultimately' indicates one should take the final letters.
'fantastic' indicates an anagram (a fantastic or improbable ordering of the letters).
The final letter of 'celebrated' is 'd'.
'editor' with letters rearranged gives 'iderot'.
'd'+'iderot'='DIDEROT'
Can you help me to learn more?
(Other definitions for diderot that I've seen before include "Denis --, French philosopher; odd rite (anag.)" , "Denis ---, Fr. encyclopaedist" , "Denis --- Fr. encyclopedist, D. editor (anag)" , "Denis --, French philosopher and encyclopedist" .)