The most common and most likely answer to this crossword clue is the 7 letter word COLLIER
C
O
L
L
I
E
R
More clues leading to the result COLLIER
- Coal miner runs after dog
- Geordie Jack, commonly, reckoned by Dog Star at last
- Hardy councillor eclipses minor
- A little manic, Ollie Reed portrays man seen with canary
- Pitman shorthand for writing on dog’s tail
- Miner’s dog seen on end of pier
- Depression settled on one reclining manual worker
- Pitman increasingly happy with new leader
- One operates underground dog races, showing front
- Dog right for a miner
Buddy explains!

The straight part
We know that "Geordie Jack, commonly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case geordie jack, commonly = collier.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does COLLIER mean?
COLLIER noun- A person in the business or occupation of producing (digging or mining) coal or making charcoal or in its transporting or commerce.
- A vessel carrying a bulk cargo of coal.
- A sailor on such a vessel.
- (used by the traveller community) A non-traveller.