Breaking red vase is hostile (7)
I believe the answer is:
adverse
'hostile' is the definition.
(I've seen this before)
'breaking red vase' is the wordplay.
'breaking' is an anagram indicator.
'red'+'vase'='redvase'
'redvase' with letters rearranged gives 'ADVERSE'.
'is' acts as a link.
(Other definitions for adverse that I've seen before include "Unfavourable or harmful, perhaps criticism" , "Unfavourable of the week" , "Detrimental" , "Contrary, harmful" , "Contrary -- inauspicious" .)