2. (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.
3. (Bot.) Hairlike processes, commonly marginal and forming a
fringe like the eyelash.
4. (Zo["o]l.) Small, vibratory, swimming organs, somewhat
resembling true cilia, as those of Ctenophora.