Mining term for a worker who pushes mine carts or assists the lead miner (先山). Contrasts with 先山, the lead miner who extracts ore.
See also: 先山
坑道で後山がトロッコを押していた。
The pusher was pushing the mine cart in the tunnel.
Compound of 後 (あと, 'behind') and 山 (やま, 'mine'), referring to the worker who follows behind the lead miner.