Wait for sailor by railway (5)
I believe the answer is:
tarry
'wait' is the definition.
(to tarry is to wait or linger)
'sailor by railway' is the wordplay.
'sailor' becomes 'tar' (slang term for a sailor).
'by' says to put letters next to each other.
'railway' becomes 'ry' (abbreviation for railway).
'tar'+'ry'='TARRY'
'for' is the link.
(Other definitions for tarry that I've seen before include "Hot and sticky" , "Wait" , "'Delay, linger (5)'" , "covered with dark liquid" , "perhaps not to split" .)