Hairspray one doesn't have, so to speak (7)
I believe the answer is:
lacquer
'hairspray' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for lacquer that I've seen before include "Shellac and alcohol hair spray" , "Shiny varnish" , "Glossy finisher" , "Glossy resin coat" , "Needing strong finish" .)