Rubbish ultimately attracting rubbish (4)
I believe the answer is:
grot
'rubbish' is the definition.
(I've seen this before)
'ultimately attracting rubbish' is the wordplay.
'ultimately' suggests the final letters.
'rubbish' becomes 'rot' (I've seen this before).
The final letter of 'attracting' is 'g'.
'g'+'rot'='GROT'
(Other definitions for grot that I've seen before include "tat" , "Refuse" , "Filth" , "Rubbish (slang); picturesque cave (poet.)" .)