Foul rubbish gathering at home (5)
I believe the answer is:
taint
'foul' is the definition.
(tainting is a kind of fouling)
'rubbish gathering at home' is the wordplay.
'rubbish' becomes 'tat' (I've seen this before).
'gathering' is an insertion indicator.
'at home' becomes 'in' ('in' can be similar in meaning to 'at home').
'tat' enclosing 'in' is 'TAINT'.
(Other definitions for taint that I've seen before include "Stigmatise" , "Contaminate, pollute" , "It isn't commonly" , "Evidence of pollution" , "Tarnish" .)