Revolving piece that secures a climber (5)
I believe the answer is:
liana
'climber' is the definition.
(climbing plant)
'revolving piece that secures a' is the wordplay.
'revolving' shows that the letters should be reversed in order.
'piece' becomes 'ail' (I can't justify this - if you can you should give a lot more credence to this answer).
'that secures' indicates putting letters inside.
'a' becomes 'an'.
'ail' written backwards gives 'lia'.
'lia' placed around 'an' is 'LIANA'.
Can you help me to learn more?
(Other definitions for liana that I've seen before include "Woody climbing (usually tropical) plant" , "Rainforest climber" , "Climbing jungle plant" , "Woody forest climber" , "Jungle creeper" .)