Hostile to touching (7)
I believe the answer is:
against
I believe this clue is a triple definition!
'hostile' is the first definition.
(thesaurus)
'to' is the second definition.
(thesaurus)
'touching' is the third definition.
(I've seen this before)
(Other definitions for against that I've seen before include "Not supporting" , "Not in favour of" , "on the other side" , "Opposite to" , "close by" .)