Three times as much left in rubbish (6)
I believe the answer is:
triple
'three times' is the definition.
(I've seen this before)
'much left in rubbish' is the wordplay.
'much left' becomes 'l' (common abbreviation. I am not sure about the 'much' bit.).
'in' indicates putting letters inside.
'rubbish' becomes 'tripe' (both can mean nonsense).
'l' placed into 'tripe' is 'TRIPLE'.
'as' is the link.
Can you help me to learn more?
(Other definitions for triple that I've seen before include "Increase threefold" , "In three parts" , "Three times" , "Threefold, treble" , "make score sixty?" .)