anything that scrubs or is used for scrubbing; specif., an apparatus that cleans the gases passing through a smokestack of a coal-burning power plant
Origin of scrubberscrub + -er
One that scrubs, especially:
a. One who cleans floors, for example, by scrubbing.
b. A brush, appliance, or abrasive that is used in cleaning.
c. An apparatus that is used for removing impurities from a gas.
scrub +"Ž -er