Cir"rus (?), n.; pl. Cirri (#). [L., lock, curl, ringlet.] [Also written cirrhus.]
1. Bot.
A tendril or clasper.
2. Zool. (a)
A soft tactile appendage of the mantle of many Mollusca, and of the parapodia of Annelida. Those near the head of annelids are Tentacular cirri; those of the last segment are caudal cirri.
(b)
The jointed, leglike organs of Cirripedia. See Annelida, and Polychaeta.
In some of the inferior animals the cirri aid in locomotion; in others they are used in feeding; in the Annelida they are mostly organs of touch. Some cirri are branchial in function.
3. Zool.
The external male organ of trematodes and some other worms, and of certain Mollusca.
4. Meteor.
See under Cloud.
© Webster 1913.