Biology A long, threadlike appendage, especially a whiplike extension of certain cells or unicellular organisms that functions as an organ of locomotion.(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.
Use "flagellum" in a sentence
"Of course, the flagellum is a great illustration of this."
"That would seem to fly in the face of all the claims that the evolution of the flagellum is a problem long since solved by biologists."
"That's why the flagellum is it's poster boy, it looks like a machine designed by a human."