Cockney bloke adopting a rich apparel (5)
I believe the answer is:
array
'rich apparel' is the definition.
(I've seen this in another clue)
'cockney bloke adopting a' is the wordplay.
'cockney bloke' becomes ''arry' ('Harry' - common masculine name - said with the 'H' dropped - a cockney accent.).
'adopting' is an insertion indicator (inserted letters are taken on or adopted).
'arry' placed around 'a' is 'ARRAY'.
(Other definitions for array that I've seen before include "Matrix; arrange" , "Deck" , "Matrix; elaborate clothing" , "Ordered arrangement (of troops)" , "Orderly or impressive display" .)