Heartless trainer in move going wrong (6)
I believe the answer is:
errant
'wrong' is the definition.
(I've seen this before)
'heartless trainer in move going' is the wordplay.
'heartless' suggests removing the centre.
'trainer' becomes 'educator' (I've seen this before).
'in move going' becomes 'rant' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'educator' with its middle taken out is 'er'.
'er'+'rant'='ERRANT'
Can you help me to learn more?
(Other definitions for errant that I've seen before include "looking for adventure" , "Travelling in search of adventure like knight of old" , "Offending" , "Off the mark, wandering" , "Like many a knight" .)