Cilium was the Latin word used by the ancient Romans for eyelid.

Though the word seemed to die off with the demise of Latin, anatomist in the 17th century started using the term again, not for eyelids however, but for eyelashes.

Meanwhile, also in the 17th century, the Danish biologist Antony van Leeuwenhoek turned his primitive magnifying lenses to pond water and discovered the microscopic world of biology. He was the first to describe, among many other things, bacteria, sperm cells, red blood cells, and protists, and on some of the protists, small hair-like structures.

In the late 18th century the cellular "hairs" came to called "cilia" given their resemblance, under the microscope, to eyelashes.

Supercilium is Latin for eyebrows and the English word "supercilious" (sneering and arrogant) comes from the arched-eyebrow look that often accompanies those who show such traits.


cnn.com