Opportunity to take railway to office (8)
I believe the answer is:
chancery
'office' is the definition.
(thesaurus)
'opportunity to take railway' is the wordplay.
'opportunity' becomes 'chance' (synonyms).
'to take' says to put letters next to each other.
'railway' becomes 'ry' (abbreviation for railway).
'chance'+'ry'='CHANCERY'
'to' acts as a link.
(Other definitions for chancery that I've seen before include "Division of the courts of justice" , "Embassy/consulate office" , "He can cry (anag.)" , "Where Jarndyce suit languished" , "Division of the British Court of Justice" .)