Trained tree to climb, ignoring one setback (7)
I believe the answer is:
relapse
'one setback' is the definition.
(I've seen this in another clue)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for relapse that I've seen before include "Fall back (into ill health)" , "Repeals (anag.)" , "fall into sin" , "go back" , "causing setback to recovery" .)