Somewhat improper (4)
I believe the answer is:
racy
'somewhat improper' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for racy that I've seen before include "Slightly indecent" , "Sexually suggestive" , "Suggestive; spirited" , "Lively" , "bawdy quality" .)