File almost all the endless rubbish (5)
I believe the answer is:
filth
'rubbish' is the definition.
(thesaurus)
'file almost all the endless' is the wordplay.
'almost all' means to remove the last letter.
'endless' means to remove the last letter.
'file' with its last letter removed is 'fil'.
'the' with its last letter taken away is 'th'.
'fil'+'th'='FILTH'
(Other definitions for filth that I've seen before include "Dirt, obscene talk" , "Disgusting dirt or obscenity" , "Squalor" , "Muck" , "Repulsive dirt" .)