Rubbish remains after tower evacuated (5)
I believe the answer is:
trash
'rubbish' is the definition.
(I know that rubbish can be written as trash)
'remains after tower evacuated' is the wordplay.
'remains' becomes 'ash' (remains of a fire).
'after' says to put letters next to each other.
'evacuated' suggests removing the centre.
'tower' with its middle taken out is 'tr'.
'ash' put after 'tr' is 'TRASH'.
(Other definitions for trash that I've seen before include "pulp" , "Anything of poor quality" , "Take the tops from < rhubarb" , "Rubbish - destroy" , "Waste material (US)" .)