Quick railway providing uniform for servants (6)
I believe the answer is:
livery
'uniform for servants' is the definition.
'livery' can be an answer for 'servants' (I have seen 'old servants' mean 'livery' so perhaps 'servants' could also mean 'livery'). I am unsure of the 'uniform for' bit.
'quick railway' is the wordplay.
'quick' becomes 'live' (quick can mean alive or living).
'railway' becomes 'ry' (abbreviation).
'live'+'ry'='LIVERY'
'providing' is the link.
Can you help me to learn more?
(Other definitions for livery that I've seen before include "old servants" , "Uniform, eg of guild" , "Horse maintenance" , "outfit in uniform" , "Irritable" .)