Club, extremely tacky, eccentric (5)
I believe the answer is:
batty
'eccentric' is the definition.
(I've seen this before)
'club extremely tacky' is the wordplay.
'club' becomes 'bat' (as in sporting equipment).
'extremely' says to hollow out the word (remove centre letters) (only the extremes of the word are used).
'tacky' with its centre removed is 'ty'.
'bat'+'ty'='BATTY'
(Other definitions for batty that I've seen before include "Crazy (sl.)" , "Seemingly descriptive of vampire" , "Dotty!" , "Nuts" , "Eccentric" .)