Charitable club go off on a railway (6)
I believe the answer is:
rotary
'charitable club' is the definition.
'Rotary' can be an answer for 'club' (Rotary Club is an example). I'm unsure of the 'charitable' bit.
'go off on a railway' is the wordplay.
'go off' becomes 'rot' (as in food going off).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'railway' becomes 'ry' (abbreviation for railway).
'rot'+'a'+'ry'='ROTARY'
Can you help me to learn more?
(Other definitions for rotary that I've seen before include "Gyratory" , "Sort of club" , "Spinning" , "Revolving (like a club?)" , "Moving in a circle" .)