Perceived blemish metres within circuit (5,4)

I believe the answer is:

floor lamp

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'perceived blemish metres within circuit' is the definition.
I can't judge whether this definition defines the answer.

'blemish metres within circuit' is the wordplay.
'blemish' becomes 'floor' (I can't explain this - if you can you should believe this answer much more).
'metres' becomes 'm'.
'within' means one lot of letters goes inside another.
'circuit' becomes 'lap' (synonyms).
'm' placed into 'lap' is 'lamp'.
'floor'+'lamp'='FLOOR-LAMP'

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

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