Shout about railway (3)
I believe the answer is:
cry
'shout' is the definition.
(synonyms)
'about railway' is the wordplay.
'about' becomes 'c' (abbreviation for circa).
'railway' becomes 'ry' (abbreviation for railway).
'c'+'ry'='CRY'
(Other definitions for cry that I've seen before include "Sob or shout" , "Don't . . . over spilt milk" , "produce tears" , "Shout - weep" , "Blubber" .)