White or green plant put outside (5)
I believe the answer is:
ivory
'white' is the definition.
(I know that bone is a type of white)
'or green plant put outside' is the wordplay.
'green plant' becomes 'ivy' (ivy is a plant. I am not sure about the 'green' bit.).
'put outside' means one lot of letters goes inside another.
'or' placed inside 'ivy' is 'IVORY'.
Can you help me to learn more?
(Other definitions for ivory that I've seen before include "Key perhaps" , "Country on the Gulf of Guinea, a former French protectorate" , "Material from elephant's tusks" , "recluse's tower?" , "Film director" .)