drain

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To draw off (a liquid) by a gradual process.
• intransitive verb To cause liquid to go out from; empty.
• intransitive verb To draw off the surface water of.
• intransitive verb To drink all the contents of.
• intransitive verb To cause (a resource or supply of something) to be used up gradually and often completely. synonym: deplete.
• intransitive verb To fatigue or spend emotionally or physically.
• intransitive verb Sports To put (a ball or shot) into a hole or basket, as in golf or basketball.
• intransitive verb To flow off or out.
• intransitive verb To become empty by the drawing off of liquid.
• intransitive verb To discharge surface or excess water.
• intransitive verb To become gradually depleted; dwindle.
• noun A pipe or channel by which liquid is drawn off.
• noun Medicine A device, such as a tube, inserted into the opening of a wound or body cavity to facilitate discharge of fluid or purulent material.
• noun The act or process of draining.
• noun A gradual outflow or loss; consumption or depletion.
• noun Something that causes a gradual loss.
• idiom (down the drain) To or into the condition of being wasted or lost.

from The Century Dictionary.

• To draw off gradually, as a liquid; remove or convey away by degrees, as through conduits, by filtration, or by any comparable process: as, to drain water from land, wine from the lees, or blood from the body; to drain away the specie of a country.
• To free, clear, or deprive by degrees, as of a liquid; empty or exhaust gradually: as, to drain land of water (the most familiar use of the word); to drain a vessel of its contents; to drain a country of its resources.
• To flow off gradually.
• To be gradually emptied, as of a liquid: as, the cask slowly drains.
• noun The act of draining or drawing off, or of emptying by drawing off; gradual or continuous outflow, withdrawal, or expenditure.
• noun That which drains, or by means of which draining is immediately effected.
• noun Specifically— A passage, pipe, or open channel for the removal of water or other liquid; especially, a pipe or channel for removing the surplus water from soils. Drains may be open ditches or sunken pipes or conduits. Those for wet lands are so made as to permit the percolation into them of water from the adjacent soil, as by the use in a covered conduit of porous earthen pipes or tiles, or of a filling of small stones, of an open cut where there is a sufficient slope, etc. See sewer.
• noun The trench in which the melted metal flows from a furnace to the molds
• noun In surgery, a hollow sound or canula used to draw off purulent matter from a deep seated abscess.
• noun Pl. The grain from the mash-tub: distinctively called brewers' drains.
• noun In ship-building, a large pipe which runs through or above the double bottom of a war-ship and is connected with the principal pumps to remove water from the various compartments.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb To flow gradually.
• intransitive verb To become emptied of liquor by flowing or dropping.
• transitive verb To draw off by degrees; to cause to flow gradually out or off; hence, to cause the exhaustion of.
• transitive verb To exhaust of liquid contents by drawing them off; to make gradually dry or empty; to remove surface water, as from streets, by gutters, etc.; to deprive of moisture; hence, to exhaust; to empty of wealth, resources, or the like.
• transitive verb To filter.
• noun The act of draining, or of drawing off; gradual and continuous outflow or withdrawal.
• noun That means of which anything is drained; a channel; a trench; a water course; a sewer; a sink.
• noun engraving The grain from the mashing tub.
• noun See under Box, Counter.
• noun (Law) an easement or servitude by which one man has a right to convey water in pipes through or over the estate of another.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A conduit allowing liquid to flow out of an otherwise contained volume.
• noun Something consuming resources and providing nothing in return.
• noun vulgar An act of urination.
• noun electronics The name of one terminal of a field effect transistor (FET).
• verb intransitive To lose liquid.
• verb transitive, ergative To cause liquid to flow out of.
• verb transitive, ergative To convert a perennially wet place into a dry one.
• verb transitive To deplete of energy or resources.