Each of a number of crossbars in a mineshaft, serving as supports or steps.
〈古〉（矿井中用作支撑或阶梯的）井壁横木
Example sentencesExamples
The entrance drops steeply down over boulders to the head of the first pitch (rigging guide) where there is a stemple which did not, however, give the pot its name.
As the passage continues there is a section of rotten flooring supported on dubious stemples just above head height.
A nerve testing traverse across a ninety foot deep stope on wooden stemples gets the adrenalin pumping, especially when trying to balance on one whilst taking photos!
A bit of extra fun was three stemples a few inches above the water which had to be ducked.
Underground, many artefacts can be seen, including stemples supporting stacked deads, ladders, pump rods and pipes, pulleys, ore tubs, windlasses, guide chutes and timbers.
Origin
Mid 17th century: perhaps related to German Stempel.