Dog runs away from pitman (6)
I believe the answer is:
collie
'dog' is the definition.
(collie is a kind of dog)
'runs away from pitman' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'away from' indicates named letters should be taken away.
'pitman' becomes 'collier' ('collier' can be a synonym of 'pitman').
'collier' with 'r' taken away is 'COLLIE'.
(Other definitions for collie that I've seen before include "Long-haired sheepdog" , "Sheep-herding dog" , "Sheepdog with long pointed muzzle" , "Scottish sheep dog" , "Popular kind of sheepdog" .)