Said to be a nice-looking coach (6)
I believe the answer is:
hansom
'coach' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe there's an association between them I don't understand?
'said to be a nice-looking' is the wordplay.
'said to be' shows a homophone (sound like).
'a nice-looking' becomes 'handsome' (I've seen this before).
'handsome' is a homophone of 'HANSOM'.
Can you help me to learn more?
(Other definitions for hansom that I've seen before include "Vehicle with back-seat driver" , "Two-wheeled horse-drawn covered cab" , "Two-wheeled one-horse carriage" , "One-horse cab" , "Victorian cab" .)