flagellum

noun, plural fla·gel·la [fluh–jel–uh] /fləˈdʒɛl ə/, fla·gel·lums.

1. Biology. a long, lashlike appendage serving as an organ of locomotion in protozoa, sperm cells, etc.
2. Botany. a runner.
3. Also called clavola. Entomology. (in an antenna) the whiplike portion above the basal joints.
4. a whip or lash.

noun plural -la (-lə) or -lums

1. biology a long whiplike outgrowth from a cell that acts as an organ of locomotion: occurs in some protozoans, gametes, spores, etc
2. botany a long thin supple shoot or runner
3. zoology the terminal whiplike part of an arthropod’s appendage, esp of the antenna of many insects

n. pl. fla•gel•la (-jĕl′ə)

1. A threadlike appendage, especially a whiplike extension of certain cells or organisms that functions as an organ of locomotion.

Plural flagella

1. A slender whiplike part extending from some single-celled organisms, such as the dinoflagellates, that moves rapidly back and forth to impart movement to the organism.