Whitish yellow plant that climbs walls (5)
I believe the answer is:
ivory
'whitish' is the definition.
(I've seen this in another clue)
'yellow plant that climbs walls' is the wordplay.
I cannot really see how this works, but
'yellow' could be 'or' (heraldic term) and 'or' is found within the answer.
'plant' could be 'ivy' (ivy is a plant) and 'ivy' is present in the leftover letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ivory that I've seen before include "Yellowish white - material from tusks" , "Creamy-white colour" , "Country on the Gulf of Guinea, a former French protectorate" , "Yellowish white colour" , "recluse's tower?" .)