Off-white climbing plant with gold in the middle (5)
I believe the answer is:
ivory
'off-white' is the definition.
(I've seen this in another clue)
'climbing plant with gold in the middle' is the wordplay.
'climbing plant' becomes 'ivy' (ivy is a type of climbing plant).
'with gold' becomes 'or' ('or' is the heraldic name for gold. I am not sure about the 'with' bit.).
'in the middle' means one lot of letters goes inside another.
'ivy' enclosing 'or' is 'IVORY'.
Can you help me to learn more?
(Other definitions for ivory that I've seen before include "Piano-key" , "Hard creamy-white dentine used for making ornaments" , "pasty" , "Creamy-white colour" , "Substance in elephant tusks" .)