Sort of retail lines that are bookish? (8)
I believe the answer is:
literary
'are bookish?' is the definition.
(thesaurus)
'sort of retail lines' is the wordplay.
'sort of' indicates anagramming the letters.
'lines' becomes 'ry' (abbreviation for railway).
'retail' anagrammed gives 'litera'.
'litera'+'ry'='LITERARY'
'that' is the link.
(Other definitions for literary that I've seen before include "To do with books, poems etc" , "Well-read" , "Concerning books" , "Relating to good creative writing" , "Concerning written material" .)