Carriage catch with gold on (6)
I believe the answer is:
landau
'carriage' is the definition.
(type of horse-drawn carriage)
'catch with gold on' is the wordplay.
'catch' becomes 'land' (land can mean to catch or obtain).
'with gold' becomes 'au' (Au is the chemical symbol for gold. I am not sure about the 'with' bit.).
'on' says to put letters next to each other.
'land'+'au'='LANDAU'
(Other definitions for landau that I've seen before include "Four-wheeled horse-drawn carriage" , "Transport" , "Old four-wheeled covered carriage" , "A four-wheel covered carriage" , "Four-wheeled vehicle with two folding hoods" .)