Idleness of one in popular part of West London (8)
I believe the answer is:
inaction
'idleness' is the definition.
(thesaurus)
'one in popular part of west london' is the wordplay.
'one' becomes 'i' (Roman numeral).
'in' means one lot of letters goes inside another.
'popular' becomes 'in' (something that's 'in' is fashionable).
'part of west london' becomes 'acton' (I can't explain this - if you can you should give a lot more credence to this answer).
'in'+'acton'='inacton'
'i' placed inside 'inacton' is 'INACTION'.
'of' is the link.
Can you help me to learn more?
(Other definitions for inaction that I've seen before include "Ionic tan (anag.)" , "doing nothing whatsoever" , "Idleness - fighting" , "Inertia" , "Sloth" .)