[1] : The Collaborative International Dictionary of English v.0.48

scale \scale\, n. cf. as. scealu, scalu, a shell, parings; akin
   to d. schaal, g. schale, ohg. scala, dan.  sw. skal a shell,
   dan. skiael a fish scale, goth. skalja tile, and e. shale,
   shell, and perhaps also to scale of a balance; but perhaps
   rather fr. of. escale, escaile, f. 'ecaille scale of a
   fish, and 'ecale shell of beans, pease, eggs, nuts, of
   german origin, and akin to goth. skalja, g. schale. see
   shale.
   1. anat. one of the small, thin, membranous, bony or horny
      pieces which form the covering of many fishes and
      reptiles, and some mammals, belonging to the dermal part
      of the skeleton, or dermoskeleton. see cycloid,
      ctenoid, and ganoid.
      1913 webster

            fish that, with their fins and shining scales,
            glide under the green wave.           --milton.
      1913 webster

   2. hence, any layer or leaf of metal or other material,
      resembling in size and thinness the scale of a fish; as, a
      scale of iron, of bone, etc.
      1913 webster

   3. zool. one of the small scalelike structures covering
      parts of some invertebrates, as those on the wings of
      lepidoptera and on the body of thysanura; the elytra of
      certain annelids. see lepidoptera.
      1913 webster

   4. zool. a scale insect. see below.
      1913 webster

   5. bot. a small appendage like a rudimentary leaf,
      resembling the scales of a fish in form, and often in
      arrangement; as, the scale of a bud, of a pine cone, and
      the like. the name is also given to the chaff on the stems
      of ferns.
      1913 webster

   6. the thin metallic side plate of the handle of a
      pocketknife. see illust. of pocketknife.
      1913 webster

   7. an incrustation deposit on the inside of a vessel in which
      water is heated, as a steam boiler.
      1913 webster

   8. metal. the thin oxide which forms on the surface of iron
      forgings. it consists essentially of the magnetic oxide,
      fe3o4. also, a similar coating upon other metals.
      1913 webster

   covering scale zool., a hydrophyllium.

   ganoid scale. zool. see under ganoid.

   scale armor mil., armor made of small metallic scales
      overlapping, and fastened upon leather or cloth.

   scale beetle zool., the tiger beetle.

   scale carp zool., a carp having normal scales.

   scale insect zool., any one of numerous species of small
      hemipterous insects belonging to the family coccidae, in
      which the females, when adult, become more or less
      scalelike in form. they are found upon the leaves and
      twigs of various trees and shrubs, and often do great
      damage to fruit trees. see orange scale,under orange.
      

   scale moss bot., any leafy-stemmed moss of the order
      hepaticae; -- so called from the small imbricated
      scalelike leaves of most of the species. see hepatica,
      2, and jungermannia.
      1913 webster
see also:
shale cycloid ctenoid ganoid lepidoptera pocketknife 
fe3o4 covering scale ganoid scale scale armor scale beetle 
scale carp scale insect coccidae orange scale orange 
scale moss hepaticae hepatica jungermannia 

[2] : WordNet (r) 2.0

scale insect
     n : small homopterous insect that usually lives and feeds on
         plants and secretes a protective waxy covering

Insect >> I Words
Insect, definition of term: Insect
insect_pag1.html

Musical Scale >> M Words
Musical Scale, definition of term: Musical Scale
musical+scale_pag1.html

Ph Scale >> P Words
Ph Scale, definition of term: Ph Scale
ph+scale_pag1.html

Major Scale >> M Words
Major Scale, definition of term: Major Scale
major+scale_pag1.html

Beaufort Scale >> B Words
Beaufort Scale, definition of term: Beaufort Scale
beaufort+scale_pag1.html

Fish Scale >> F Words
Fish Scale, definition of term: Fish Scale
fish+scale_pag1.html

Diatonic Scale >> D Words
Diatonic Scale, definition of term: Diatonic Scale
diatonic+scale_pag1.html