The Collaborative International Dictionary of English v.0.48:

Mantel \Man"tel\, n. [The same word as mantle a garment; cf. F.
   manteau de chemin['e]e. See Mantle.] (Arch.)
   The finish around a fireplace, covering the chimney-breast in
   front and sometimes on both sides; especially, a shelf above
   the fireplace, and its supports. The shelf is called also a
   mantelpiece or mantlepiece. [Written also mantle.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

mantle \man"tle\, n. [OE. mantel, OF. mantel, F. manteau, fr. L.
   mantellum, mantelum, a cloth, napkin, cloak, mantle (cf.
   mantele, mantile, towel, napkin); prob. from manus hand + the
   root of tela cloth. See Manual, Textile, and cf.
   Mandil, Mantel, Mantilla.]
   [1913 Webster]
   1. A loose garment to be worn over other garments; an
      enveloping robe; a cloak. Hence, figuratively, a covering
      or concealing envelope.
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            [The] children are clothed with mantles of satin.
                                                  --Bacon.
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            The green mantle of the standing pool. --Shak.
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            Now Nature hangs her mantle green
            On every blooming tree.               --Burns.
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   2. (Her.) Same as Mantling.
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   3. (Zool.)
      (a) The external fold, or folds, of the soft, exterior
          membrane of the body of a mollusk. It usually forms a
          cavity inclosing the gills. See Illusts. of
          Buccinum, and Byssus.
      (b) Any free, outer membrane.
      (c) The back of a bird together with the folded wings.
          [1913 Webster]

   4. (Arch.) A mantel. See Mantel.
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   5. The outer wall and casing of a blast furnace, above the
      hearth. --Raymond.
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   6. (Hydraulic Engin.) A penstock for a water wheel.
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   7. (Geol.) The highly viscous shell of hot semisolid rock,
      about 1800 miles thick, lying under the crust of the Earth
      and above the core. Also, by analogy, a similar shell on
      any other planet.
      [PJC]

The Collaborative International Dictionary of English v.0.48:

Mantle \Man"tle\, v. t. [imp. & p. p. Mantled; p. pr. & vb. n.
   Mantling.]
   To cover or envelop, as with a mantle; to cloak; to hide; to
   disguise. --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Mantle \Man"tle\, v. i.
   1. To unfold and spread out the wings, like a mantle; -- said
      of hawks. Also used figuratively.
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            Ne is there hawk which mantleth on her perch.
                                                  --Spenser.
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            Or tend his sparhawk mantling in her mew. --Bp.
                                                  Hall.
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            My frail fancy fed with full delight.
            Doth bathe in bliss, and mantleth most at ease.
                                                  --Spenser.
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   2. To spread out; -- said of wings.
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            The swan, with arched neck
            Between her white wings mantling proudly, rows.
                                                  --Milton.
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   3. To spread over the surface as a covering; to overspread;
      as, the scum mantled on the pool.
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            Though mantled in her cheek the blood. --Sir W.
                                                  Scott.
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   4. To gather, assume, or take on, a covering, as froth, scum,
      etc.
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            There is a sort of men whose visages
            Do cream and mantle like a standing pond. --Shak.
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            Nor bowl of wassail mantle warm.      --Tennyson.
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WordNet (r) 3.0 (2006):

mantle
    n 1: the cloak as a symbol of authority; "place the mantle of
         authority on younger shoulders"
    2: United States baseball player (1931-1997) [syn: Mantle,
       Mickey Mantle, Mickey Charles Mantle]
    3: the layer of the earth between the crust and the core
    4: anything that covers; "there was a blanket of snow" [syn:
       blanket, mantle]
    5: (zoology) a protective layer of epidermis in mollusks or
       brachiopods that secretes a substance forming the shell [syn:
       mantle, pallium]
    6: shelf that projects from wall above fireplace; "in Britain
       they call a mantel a chimneypiece" [syn: mantel,
       mantelpiece, mantle, mantlepiece, chimneypiece]
    7: hanging cloth used as a blind (especially for a window) [syn:
       curtain, drape, drapery, mantle, pall]
    8: a sleeveless garment like a cloak but shorter [syn: cape,
       mantle]
    v 1: spread over a surface, like a mantle
    2: cover like a mantle; "The ivy mantles the building"