DRAIN

noun

1. A conduit allowing liquid to flow out of an otherwise contained volume; a plughole (UK)
2. An access point or conduit for rainwater that drains directly downstream in a (drainage) basin without going through sewers or water treatment in order to prevent or belay floods.
3. Something consuming resources and providing nothing in return.

verb

1. To lose liquid.
2. To flow gradually.
3. To cause liquid to flow out of.