Definition of "impeller" [im•pel•ler]

• One that impels, as a rotating device used to force a fluid in a desired direction under pressure. (noun)
• A rotor or rotor blade. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "In these pumps, the impeller is a wheel with blades radiating from the centre to the periphery which, when rotated at high speed, impart movement to the water and produce an outward flow due to centrifugal forces; the angle between the direction of entry and exit of water flow is 90 degrees."
• "The only moving component within the pump is the impeller, which is levitated and rotated within the pump chamber in a contact-free manner."
• "The impeller is the device that creates suction and if it becomes damaged, you have to replace your sump pump."