A marrow is a trusted partner working alongside a miner, historically in coal seams where pairs worked together to extract coal and load tubs. The term signifies a deep level of trust and mutual reliance in dangerous underground conditions. While largely an older regional term in British coalfields, it survives in mining lore to describe the bond between workers who watch each other's backs.
Heard on the job
I've been working this seam with my marrow for five years and we split the tally evenly.
Also heard as
- half-marrow