Train that may be held up by attendant (6)
I believe the answer is:
bridal
'train that may be held up by attendant' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
This is all the clue.
Can you help me to learn more?
(Other definitions for bridal that I've seen before include "Woman in White" , "as new partner in union" , "of the train puller?" , "The suite for the honeymooners" , "Newly-wed" .)