It's a load of rubbish, one gathers (7)
I believe the answer is:
dustman
'it's a load' is the definition.
I can't tell whether this defines the answer.
'rubbish one gathers' is the wordplay.
'rubbish' becomes 'dust' (dust is a kind of rubbish).
'one gathers' becomes 'man' (I am not sure about this - if you are sure you should believe this answer much more).
'dust'+'man'='DUSTMAN'
'of' is the link.
Can you help me to learn more?
(Other definitions for dustman that I've seen before include "Refuse collector" , "Garbage collector" , "Bin emptier" , "I clear what's left" , "Rubbish collector" .)