Traveller's one-liner? (8)
I believe the answer is:
monorail
'traveller's one-liner?' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
This is the entire clue.
Can you help me to learn more?
(Other definitions for monorail that I've seen before include "Suspended railway" , "Hanging transport system" , "Type of railway" , "Form of transport" , "train" .)