Meaninghole · pitOn'yomiコウCommon compounds (5)炭坑 たんこうcoal-mine shaft廃坑 はいこうclosure of a mine; abandoned mine; disused mine坑道 こうどうtunnel; (mining) gallery; level; shaft; pit坑内 こうないwithin a pit or (mine) shaft坑口 こうこうpithead; minehead