Luxuriant hairstyle publicity worker covers (8)
I believe the answer is:
abundant
'luxuriant' is the definition.
(similar in meaning)
'hairstyle publicity worker covers' is the wordplay.
'hairstyle' becomes 'bun'.
'publicity' becomes 'ad' (short for advert).
'worker' becomes 'ant' (worker is a type of ant).
'covers' indicates putting letters inside.
'ad'+'ant'='adant'
'bun' inserted into 'adant' is 'ABUNDANT'.
(Other definitions for abundant that I've seen before include "well-provided" , "Present in large quantities" , "Existing in large amounts" , "Present in great quantity" , "Exuberant" .)