Design compound outside of Lille (5)
I believe the answer is:
style
'design' is the definition.
(styling is a kind of designing)
'compound outside of lille' is the wordplay.
'compound' becomes 'sty' (I am not sure about this - if you are sure you should believe this answer much more).
'outside of' says to hollow out the word (remove centre letters) (only letters on the outside of the word).
'lille' with its centre removed is 'le'.
'sty'+'le'='STYLE'
Can you help me to learn more?
(Other definitions for style that I've seen before include "Vogue or grace" , "way of writing" , "Particular kind, of fashion say" , "Former writer" , "Pointed pen" .)