a pit or hollow in which liquid collects, in particular 集水坑,尤指 ■the base of an internal-combustion engine, which serves as a reservoir of oil for the lubrication system (内燃机润滑系统的)集油槽,油底壳 ■a depression in the floor of a mine or cave in which water collects (矿井,山洞中的)水窝 ■a cesspool 污水坑
语源
Middle English (in the sense 'marsh'): from Middle Dutch or Low German sump, or (in the mining sense) from German Sumpf; related to swamp