Birds flying around last of the rubbish (6)
I believe the answer is:
debris
'rubbish' is the definition.
(I know that debris is a type of rubbish)
'birds flying around last of the' is the wordplay.
'flying' is an anagram indicator (letters fly around into new positions).
'around' means one lot of letters goes inside another.
'last of' says to take the final letters.
The last letter of 'the' is 'e'.
'birds' anagrammed gives 'dbris'.
'dbris' going around 'e' is 'DEBRIS'.
(Other definitions for debris that I've seen before include "Broken remains" , "'Ruins, rubble (6)'" , "Rubble, heap of broken pieces" , "Scattered wreckage" , "Brides with pieces of rubble" .)