Fantastic magazine endlessly redistributed (7)
I believe the answer is:
amazing
'fantastic' is the definition.
(I've seen this before)
'magazine endlessly redistributed' is the wordplay.
'endlessly' means to remove the last letter.
'redistributed' indicates anagramming the letters (letters distributed to new positions).
'magazine' with its last letter removed is 'magazin'.
'magazin' anagrammed gives 'AMAZING'.
(Other definitions for amazing that I've seen before include "Unbelievable!" , "Astounding, awe-inspiring" , "Causing great surprise" , "Astonishing, remarkable" , "Prodigious" .)