Source : Webster's Revised Unabridged Dictionary (1913)

Cirri \Cir"ri\, n. pl.
   See {Cirrus}.

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

   2. (Zo["o]l.)
      (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}.

   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.

   3. (Zo["o]l.) The external male organ of trematodes and some
      other worms, and of certain Mollusca.

   4. (Meteor.) See under {Cloud}.

Source : WordNet®

cirri
     See {cirrus}

cirrus
     n 1: usually coiled [syn: {cirrhus}]
     2: a wispy white cloud (usually of fine ice crystals) at a high
        altitude (4 to 8 miles) [syn: {cirrus cloud}]
     3: a slender flexible animal appendage as on barnacles or
        crinoids or many insects; often tactile
     [also: {cirri} (pl)]