Reversal in clue to react? (5,4)
I believe the answer is:
about turn
'reversal' is the definition.
(I know that about turn is a type of reversal)
'clue to react?' is the wordplay.
'clue' becomes 'about' (I can't justify this - if you can you should believe this answer much more).
'to react?' becomes 'turn' (reacting is a kind of turning).
'about'+'turn'='ABOUT-TURN'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for about turn that I've seen before include "Total change of direction" , "Major change of attitude" , "Face the opposite way" , "Total change of policy" , "Contrary progression" .)