Traditionalist response to a railway (11)
I believe the answer is:
reactionary
'traditionalist' is the definition.
(thesaurus)
'response to a railway' is the wordplay.
'response' becomes 'reaction' (synonyms).
'railway' becomes 'ry' (abbreviation for railway).
'reaction'+'a'+'ry'='REACTIONARY'
(Other definitions for reactionary that I've seen before include "No progressive" , "Opposing progress or reform" , "Ultra-conservative" , "right-winger?" , "Diehard" .)