Miner (6)
'miner' is the definition.
(collier is a kind of miner)
This is all the clue.
(Other definitions for collier that I've seen before include "Miner; coal ship" , "Geordie Jack, commonly" , "Ship carrying coal" , "Painter" , "unable to avoid contact with mine" .)
'miner' is the definition.
(I know that pitman is a type of miner)
This is the entire clue.
(Other definitions for pitman that I've seen before include "Miner" , "Mine host perhaps" , "Mine worker" , "Racehorse trainer" .)