Training doctor poorly (5)
I believe the answer is:
drill
'training' is the definition.
(I've seen this before)
'doctor poorly' is the wordplay.
'doctor' becomes 'dr' ('Dr' can be a synonym of 'doctor').
'poorly' becomes 'ill' ('ill' can be a synonym of 'poorly').
'dr'+'ill'='DRILL'
(Other definitions for drill that I've seen before include "Tool; fabric; bore" , "Hole-making tool" , "Bore (a hole); fabric" , "Military training; bore" , "Twill-weave cotton cloth" .)