Comprehensive designed to impress (5)
I believe the answer is:
grand
I believe this clue is a double definition.
'comprehensive' is the first definition.
(grand can mean comprehensive or inclusive)
'designed to impress' is the second definition.
(grand can mean impressive or fancy)
(Other definitions for grand that I've seen before include "Marvellous" , "Magnificent, imposing" , "Designed to impress" , "Splendid - piano" , "sum of money" .)