Copper cordoning off large featureless entertainment area (8)
I believe the answer is:
clubland
'entertainment area' is the definition.
(area with lots of night clubs)
'copper cordoning off large featureless' is the wordplay.
'copper' becomes 'Cu' (chemical symbol).
'cordoning off' means one lot of letters goes inside another (inserted letters are cordoned off by other letters).
'large' becomes 'L' (eg in clothes sizes).
'featureless' becomes 'bland' (bland can mean dull or plain).
'cu' placed around 'l' is 'clu'.
'clu'+'bland'='CLUBLAND'
(Other definitions for clubland that I've seen before include "Social area of St James's" , "It tends to be busy on Saturday night" , "Area with lots of night spots" .)