It takes back endless red farm vehicle (9)
I believe the answer is:
retractor
'it' is the definition.
The definition suggests a singular noun which matches the answer.
'back endless red farm vehicle' is the wordplay.
'back' shows that the letters should be reversed in order.
'endless' says to take the centre.
'red' becomes 'cherry' (shade of red).
'farm vehicle' becomes 'tractor' (vehicle used on a farm).
The central letters of 'cherry' are 'er'.
'er' in reverse letter order is 're'.
're'+'tractor'='RETRACTOR'
'takes' is the link.
Can you help me to learn more?
(Other definitions for retractor that I've seen before include "It must pull back" , "Instrument" , "that springs back in reverse?" , "One withdraws" , "Muscle" .)