cilium

noun4

1. •
   A short microscopic hairlike organelle projecting from a eukaryotic cell (such as a unicellular organism or one cell of a multicelled organism) which serve either for propulsion by causing currents in the surrounding fluid or as sensors.

   • The clockwise beating of cilia results in a net flow of extraembryonic fluid leftwards […] — 2006
2. •
   One of the fine hairs along an insect's wing.
3. •
   One of the hairs or similar protrusions along the margin of an organ.
4. •
   An eyelash.