Darker and more pretentious? Bill will block it (9)

I believe the answer is:

shadowier

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'darker and more pretentious?' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'bill will block it' is the wordplay.
'bill' becomes 'ad' (advertisement stuck on wall).
'will block' means one lot of letters goes inside another.
'it' becomes 'showier' (I am not sure about this - if you are sure you should believe this answer much more).
'ad' placed within 'showier' is 'SHADOWIER'.

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I've seen this clue in The Hindu.

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