backwash

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

• noun A backward flow of water, as from the action of oars.
• noun A backward flow of air, as from the propeller of an aircraft.
• noun A result of an event; an aftermath.
• noun Informal A backward flow of liquid from the mouth into a bottle or other drinking vessel at the end of a swig.

from The Century Dictionary.

• To cleanse from oil, as wool after combing.
• To subject to the back-wash of a boat which is ahead or is passing.
• noun In worsted manuf., a process of cleaning the carded sliver of wool by passing it through hot suds.
• noun The disturbed water thrown aft by the action of the oars, paddle-wheels, or propeller of a boat.

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

• noun The flow of water propelled backward by the propeller, paddle wheel, or oars of a boat.
• noun (Aeron.) The backward flowing air within the wash of an airplane, caused mostly by the engine.
• transitive verb To clean the oil from (wool) after combing.
• transitive verb (Chem.) To clean (a filter, a chromatography column, a water softener, etc.) by passing liquid through in the reverse of the normal direction of flow. This procedure dislodges particles which clog the pores of the filter or column packing, removing them from the filter or column.

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

• noun nautical The backward flow of water from oars or propeller.
• noun The similar flow of air from an aircraft engine.
• noun The result or consequence of an event; an aftermath.
• noun The saliva, spit or food particles that have flowed back into a drink after someone has drunk from it.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the wave that spreads behind a boat as it moves forward
• noun the consequences of an event (especially a catastrophic event)
• noun the flow of air that is driven backwards by an aircraft propeller