Drain, drain cap, Floor drain (0).

排水口，排水盖，地漏(0)。

youdao

Have you heard of oil cap or drain plug not tightened?

你曾听说过机油盖或泄油螺丝没栓紧的事吗？

youdao

When using valve nozzle for easy drain, please insert nozzle into the sealing cap and screw the cap onto the discharge valve with gasket and tighten it.

如使用阀门接管，请将其连同垫圈套在螺纹盖中，拧回放料阀并拧紧。

youdao

And in Greenland, scientists suspect the melt waters that drain through holes, or moulins, in the ice cap to the bedrock may have contributed to the speed-up of glaciers in that region, too.

BBC: Under-ice flood speeds up glacier