The Collaborative International Dictionary of English v.0.48:

perch \perch\ (p[~e]rch), n. [Written also pearch.] [OE.
   perche, F. perche, L. perca, fr. Gr. pe`rkh; cf. perkno`s
   dark-colored, Skr. p[.r][,c]ni spotted, speckled, and E.
   freckle.] (Zool.)
   1. Any fresh-water fish of the genus Perca and of several
      other allied genera of the family Percid[ae], as the
      common American or yellow perch (Perca flavescens syn.
      Perca Americana), and the European perch (Perca
      fluviatilis).
      [1913 Webster]

   2. Any one of numerous species of spiny-finned fishes
      belonging to the Percid[ae], Serranid[ae], and related
      families, and resembling, more or less, the true perches.
      [1913 Webster]

   Black perch.
      (a) The black bass.
      (b) The flasher.
      (c) The sea bass.

   Blue perch, the cunner.

   Gray perch, the fresh-water drum.

   Red perch, the rosefish.

   Red-bellied perch, the long-eared pondfish.

   Perch pest, a small crustacean, parasitic in the mouth of
      the perch.

   Silver perch, the yellowtail.

   Stone perch, or Striped perch, the pope.

   White perch, the Roccus Americanus, or Morone
      Americanus, a small silvery serranoid market fish of the
      Atlantic coast.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Perch \Perch\ (p[~e]rch), n. [F. perche, L. pertica.]
   1. A pole; a long staff; a rod; esp., a pole or other support
      for fowls to roost on or to rest on; a roost;
      figuratively, any elevated resting place or seat.
      [1913 Webster]

            As chauntecleer among his wives all
            Sat on his perche, that was in his hall. --Chaucer.
      [1913 Webster]

            Not making his high place the lawless perch
            Of winged ambitions.                  --Tennyson.
      [1913 Webster]

   2.
      (a) A measure of length containing five and a half yards;
          a rod, or pole.
      (b) In land or square measure: A square rod; the 160th
          part of an acre.
      (c) In solid measure: A mass 161/2 feet long, 1 foot in
          height, and 11/2 feet in breadth, or 243/4 cubic feet
          (in local use, from 22 to 25 cubic feet); -- used in
          measuring stonework.
          [1913 Webster]

   3. A pole connecting the fore gear and hind gear of a spring
      carriage; a reach.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Perch \Perch\, v. i. [imp. & p. p. Perched (p[~e]rcht); p. pr.
   & vb. n. Perching.] [F. percher. See Perch a pole.]
   To alight or settle, as a bird; to sit or roost.
   [1913 Webster]

         Wrens make prey where eagles dare not perch. --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Perch \Perch\, v. t.
   1. To place or to set on, or as on, a perch.
      [1913 Webster]

   2. To occupy as a perch. --Milton.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sprat \Sprat\ (spr[a^]t), n. [OE. sprot, sprotte, D. sprot; akin
   to G. sprotte.] (Zool.)
   (a) A small European herring (Clupea sprattus) closely
       allied to the common herring and the pilchard; -- called
       also garvie. The name is also applied to small herring
       of different kinds.
   (b) A California surf-fish (Rhacochilus toxotes); -- called
       also alfione, and perch.
       [1913 Webster]

   Sprat borer (Zool.), the red-throated diver; -- so called
      from its fondness for sprats. See Diver.

   Sprat loon. (Zool.)
   (a) The young of the great northern diver. [Prov. Eng.]
   (b) The red-throated diver. See Diver.

   Sprat mew (Zool.), the kittiwake gull.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Rod \Rod\, n. [The same word as rood. See Rood.]
   1. A straight and slender stick; a wand; hence, any slender
      bar, as of wood or metal (applied to various purposes).
      Specifically:
      (a) An instrument of punishment or correction;
          figuratively, chastisement.
          [1913 Webster]

                He that spareth his rod hateth his son. --Prov.
                                                  xiii. 24.
          [1913 Webster]
      (b) A kind of sceptor, or badge of office; hence,
          figuratively, power; authority; tyranny; oppression.
          "The rod, and bird of peace." --Shak.
      (c) A support for a fishing line; a fish pole. --Gay.
      (d) (Mach. & Structure) A member used in tension, as for
          sustaining a suspended weight, or in tension and
          compression, as for transmitting reciprocating motion,
          etc.; a connecting bar.
      (e) An instrument for measuring.
          [1913 Webster]

   2. A measure of length containing sixteen and a half feet; --
      called also perch, and pole.
      [1913 Webster]

   Black rod. See in the Vocabulary.

   Rods and cones (Anat.), the elongated cells or elements of
      the sensory layer of the retina, some of which are
      cylindrical, others somewhat conical.
      [1913 Webster]

WordNet (r) 3.0 (2006):

perch
    n 1: support consisting of a branch or rod that serves as a
         resting place (especially for a bird)
    2: a linear measure of 16.5 feet [syn: perch, rod, pole]
    3: a square rod of land [syn: perch, rod, pole]
    4: an elevated place serving as a seat
    5: any of numerous fishes of America and Europe
    6: spiny-finned freshwater food and game fishes
    7: any of numerous spiny-finned fishes of various families of
       the order Perciformes
    v 1: sit, as on a branch; "The birds perched high in the tree"
         [syn: perch, roost, rest]
    2: to come to rest, settle; "Misfortune lighted upon him" [syn:
       alight, light, perch]
    3: cause to perch or sit; "She perched her hat on her head"