Luxurious work originally unveiled fast (7)
I believe the answer is:
opulent
'luxurious' is the definition.
(I know that luxurious can be written as opulent)
'work originally unveiled fast' is the wordplay.
'work' becomes 'op' (common abbreviation for 'opus').
'originally' says to take the initial letters.
'fast' becomes 'lent' (Lent is a period of fasting in Christianity).
The initial letter of 'unveiled' is 'u'.
'op'+'u'+'lent'='OPULENT'
(Other definitions for opulent that I've seen before include "Luxurious or profuse" , "'Loaded'" , "Wealthy or luxuriant" , "Well-to-do or lavish" , "Well-to-do, rich" .)