Hairdresser in a pen catalogue? (7)
I believe the answer is:
stylist
'hairdresser' is the definition.
(I know that hairdresser can be written as stylist)
'pen catalogue?' is the wordplay.
'pen' becomes 'sty' (both can mean an animal enclosure).
'catalogue?' becomes 'list' (a catalogue is a list of items).
'sty'+'list'='STYLIST'
'in a' acts as a link.
(Other definitions for stylist that I've seen before include "(Hair) designer" , "One who creates elegance as of clothes or design" , "Clothes designer; hairdresser" , "Fashion expert" , "Elegant writer" .)