backwash

noun

1. Nautical. water thrown backward by the motion of oars, propellers, paddle wheels, etc.
2. Aeronautics. the portion of the wash of an aircraft that flows to the rear, usually created by the power plant.Compare wash(def 31).
3. a condition, usually undesirable, that continues long after the event which caused it.

verb (used with object)

4. to affect, as by hitting, rocking, or splashing, with a backwash: a powerful cutter backwashing the skiers.
5. to clean out (a clogged filter) by reversing the flow of fluid: Backwash the swimming pool’s filters regularly.

noun

1. a sucking movement of water, such as that of retreating wavesCompare swash (def. 4)
2. water washed backwards by the motion of oars or other propelling devices
3. the backward flow of air set up by an aircraft’s engines
4. a condition resulting from a previous event; repercussion

verb

5. (tr) to remove oil from (combed wool)

n.

1876, “motion of a receeding wave,” from back (adj.) + wash (n.).