Part of Japan, a magnificent country (6)
I believe the answer is:
panama
'country' is the definition.
(Panama is an example)
'part of japan a magnificent' is the wordplay.
'part of' indicates a hidden word.
'PANAMA' is hidden in the letters of 'japan a magnificent'.
(Other definitions for panama that I've seen before include "Land - hat - cigar" , "Hat; Central Am. canal" , "Wide-brimmed hat" , "Central American state" , "Country - hat - canal - cigar" .)