Climber to copy, getting head down (3)
I believe the answer is:
pea
'climber' is the definition.
(the pea plant is a climbing plant)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for pea that I've seen before include "Seed eaten as vegetable" , "Climber" , "Tiny stone" , "Cause of a princess's insomnia?" , "12 in a pod" .)