Where, if the train doesn't stop, it's only by accident (8)
I believe the answer is:
terminus
'where if the train doesn't stop it's only by accident' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
This is the entire clue.
Can you help me to learn more?
(Other definitions for terminus that I've seen before include "eg Paddington" , "End station" , "End (of rail line)" , "End of bus/rail route" , "End of the line for tram or bus" .)