Hostile, unfavourable (8)
I believe the answer is:
inimical
I believe this is a double definition.
'hostile' is the first definition.
(similar in meaning)
'unfavourable' is the second definition.
(I've seen this before)
(Other definitions for inimical that I've seen before include "Hostile or in opposition" , "Hostile, antagonistic" , "Hostile, unfavourable" , "In claim I am strangely hostile" , "'Unfriendly, hostile (8)'" .)