Unrivalled in Nepal - or different! (9)
I believe the answer is:
nonpareil
'unrivalled' is the definition.
('nonpareil' can be a synonym of 'unrivalled')
'in nepal or different' is the wordplay.
'different' indicates an anagram.
'in'+'nepal'+'or'='innepalor'
'innepalor' is an anagram of 'NONPAREIL'.
(Other definitions for nonpareil that I've seen before include "Unrivalled; old type size" , "unmatched!" , "Paragon" , "beyond compare" , "Unique type" .)