C

n. pl. Cilium, the sing., is rarely used.

 - (Anat.) The eyelashes.

 - (Biol.) Small, generally microscopic, vibrating appendages lining certain organs, as the air passages of the higher animals, and in the lower animals often covering also the whole or a part of the exterior. They are also found on some vegetable organisms. In the Infusoria, and many larval forms, they are locomotive organs.

 - (Bot.) Hair like processes, commonly marginal and forming a fringe like the eyelash.

 - (Zool.) Small, vibratory, swimming organs, somewhat resembling true cilia, as those of Ctenophora.