The Collaborative International Dictionary of English v.0.48:

Shade \Shade\ (sh[=a]d), n. [OE. shade, shadewe, schadewe, AS.
   sceadu, scead; akin to OS. skado, D. schaduw, OHG. scato,
   (gen. scatewes), G. schatten, Goth. skadus, Ir. & Gael.
   sgath, and probably to Gr. sko`tos darkness. [root]162. Cf.
   Shadow, Shed a hat.]
   1. Comparative obscurity owing to interception or
      interruption of the rays of light; partial darkness caused
      by the intervention of something between the space
      contemplated and the source of light.
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   Note: Shade differs from shadow as it implies no particular
         form or definite limit; whereas a shadow represents in
         form the object which intercepts the light. When we
         speak of the shade of a tree, we have no reference to
         its form; but when we speak of measuring a pyramid or
         other object by its shadow, we have reference to its
         form and extent.
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   2. Darkness; obscurity; -- often in the plural.
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            The shades of night were falling fast. --Longfellow.
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   3. An obscure place; a spot not exposed to light; hence, a
      secluded retreat.
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            Let us seek out some desolate shade, and there
            Weep our sad bosoms empty.            --Shak.
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   4. That which intercepts, or shelters from, light or the
      direct rays of the sun; hence, also, that which protects
      from heat or currents of air; a screen; protection;
      shelter; cover; as, a lamp shade.
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            The Lord is thy shade upon thy right hand. --Ps.
                                                  cxxi. 5.
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            Sleep under a fresh tree's shade.     --Shak.
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            Let the arched knife well sharpened now assail the
            spreading shades of vegetables.       --J. Philips.
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   5. Shadow. [Poetic.]
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            Envy will merit, as its shade, pursue. --Pope.
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   6. The soul after its separation from the body; -- so called
      because the ancients it to be perceptible to the sight,
      though not to the touch; a spirit; a ghost; as, the shades
      of departed heroes.
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            Swift as thought the flitting shade
            Thro' air his momentary journey made. --Dryden.
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   7. (Painting, Drawing, etc.) The darker portion of a picture;
      a less illuminated part. See Def. 1, above.
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   8. Degree or variation of color, as darker or lighter,
      stronger or paler; as, a delicate shade of pink.
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            White, red, yellow, blue, with their several
            degrees, or shades and mixtures, as green only in by
            the eyes.                             --Locke.
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   9. A minute difference or variation, as of thought, belief,
      expression, etc.; also, the quality or degree of anything
      which is distinguished from others similar by slight
      differences; as, the shades of meaning in synonyms.
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            New shades and combinations of thought. --De
                                                  Quincey.
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            Every shade of religious and political opinion has
            its own headquarters.                 --Macaulay.
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   The Shades, the Nether World; the supposed abode of souls
      after leaving the body.
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