A looser arrangement for spray can (7)
I believe the answer is:
aerosol
'spray can' is the definition.
(synonyms)
'a looser arrangement' is the wordplay.
'arrangement' indicates an anagram.
'looser' is an anagram of 'erosol'.
'a'+'erosol'='AEROSOL'
'for' is the link.
(Other definitions for aerosol that I've seen before include "Atomiser" , "Air spray" , "What makes mist" , "Liquid in a container under pressure" , "fog?" .)