m]
, -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. |

flagellum fla·gel·lum (flə-jěl'əm)
n. pl. fla·gel·la (-jěl'ə)
A threadlike appendage, especially a whiplike extension of certain cells or organisms that functions as an organ of locomotion.