goaf

[gohf]

noun, plural goaves. Mining.

Origin of goaf

First recorded in 1830–40; origin uncertain

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

The nearer we get to the goaf (waste ground), the more likely we are to get crushed.
The Boy With the U.S. Miners
Francis Rolt-Wheeler