Sport of Arabic church by eastern railway (7)
I believe the answer is:
archery
'sport' is the definition.
(archery is a kind of sport)
'arabic church by eastern railway' is the wordplay.
'arabic' becomes 'ar' (abbreviation in Chambers).
'church' becomes 'ch' (common abbreviation).
'by' means one lot of letters go next to another.
'eastern' becomes 'e'.
'railway' becomes 'ry' (abbreviation for railway).
'ar'+'ch'+'e'+'ry'='ARCHERY'
'of' acts as a link.
(Other definitions for archery that I've seen before include "Toxophily" , "The sport of shooting arrows with a bow" , "Shooting with bows and arrows" , "Bowmanship" , "Target sport - Olympic event in from 1900-08, in 1920 and since 1972" .)