The Collaborative International Dictionary of English v.0.48:

Cirri \Cir"ri\, n. pl.
   See Cirrus.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cirrus \Cir"rus\, n.; pl. Cirri. [L., lock, curl, ringlet.]
   [Also written cirrhus.]
   [1913 Webster]
   1. (Bot.) A tendril or clasper.
      [1913 Webster]

   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 Polych[ae]ta.
          [1913 Webster]

   Note: 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.
         [1913 Webster]

   3. (Zool.) The external male organ of trematodes and some
      other worms, and of certain Mollusca.
      [1913 Webster]

   4. (Meteor.) See under Cloud.
      [1913 Webster]