Old Indian copper lacking restraint pulled over tree (7)
I believe the answer is:
annatto
'tree' is the definition.
(I've seen this before)
'old indian copper lacking restraint pulled over' is the wordplay.
'old indian copper' becomes 'anna' (historical coin of India).
'lacking restraint' becomes 'ott' (I can't justify this - if you can you should give a lot more credence to this answer).
'pulled over' says the letters should be written in reverse.
'ott' back-to-front is 'tto'.
'anna'+'tto'='ANNATTO'
Can you help me to learn more?
(Other definitions for annatto that I've seen before include "Orange colouring" , "Food colourant" , "food colouring" , "Food dye from red pulp of tropical fruit" , "Orange-red dye" .)