Hotel is extraordinarily unfriendly (7)
I believe the answer is:
hostile
'unfriendly' is the definition.
('hostile' can be similar in meaning to 'unfriendly')
'hotel is extraordinarily' is the wordplay.
'extraordinarily' is an anagram indicator.
'hotel'+'is'='hotelis'
'hotelis' anagrammed gives 'HOSTILE'.
(Other definitions for hostile that I've seen before include "Aggressive" , "Enemy" , "The soil strangely is unfriendly" , "Inimical" , "Belligerent" .)