Get down from oak originally in tree-lined avenue (6)
I believe the answer is:
groove
'get down' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for groove that I've seen before include "Long narrow cut or depression" , "'Channel, furrow (6)'" , "Long shallow depression or routine" , "to be in this settled routine?" , "Long narrow depression - dance and/or play popular music" .)