The Collaborative International Dictionary of English v.0.48:

Sapphire \Sap"phire\, a.
   Of or resembling sapphire; sapphirine; blue. "The sapphire
   blaze." --Gray.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sapphire \Sap"phire\ (? or ?; 277), n. [OE. saphir, F. saphir,
   L. sapphirus, Gr. ?, of Oriental origin; cf. Heb.
   sapp[imac]r.]
   1. (Min.) Native alumina or aluminium sesquioxide, Al2O3;
      corundum; esp., the blue transparent variety of corundum,
      highly prized as a gem.
      [1913 Webster]

            Of rubies, sapphires, and of pearl['e]s white.
                                                  --Chaucer.
      [1913 Webster]

   Note: Sapphire occurs in hexagonal crystals and also in
         granular and massive forms. The name sapphire is
         usually restricted to the blue crystals, while the
         bright red crystals are called Oriental rubies (see
         under Ruby), the amethystine variety Oriental
         amethyst (see under Amethyst), and the dull massive
         varieties corundum (a name which is also used as a
         general term to include all varieties). See Corundum.
         [1913 Webster]

   2. The color of the gem; bright blue.
      [1913 Webster]

   3. (Zool.) Any humming bird of the genus Hylocharis, native
      of South America. The throat and breast are usually bright
      blue.
      [1913 Webster]

   Star sapphire, or Asteriated sapphire (Min.), a kind of
      sapphire which exhibits asterism.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Corundum \Co*run"dum\ (k[-o]*r[u^]n"d[u^]m), n.; pl. Corundums
   (k[-o]*r[u^]n"d[u^]mz). [Also corindon.] [From Hind. kurand
   corundum stone.] (Min.)
   The mineral alumina (Al2O3), as found native in a
   crystalline state. Transparent varieties are used as
   gemstones, including sapphire, which is the fine blue
   variety; the oriental ruby, or red sapphire; the oriental
   amethyst, or purple sapphire; and adamantine spar, the
   hair-brown variety. It is the hardest substance found native,
   next to the diamond.
   [1913 Webster +PJC]

   Note: The name corundum is sometimes restricted to the
         non-transparent or coarser kinds. Emery is a
         dark-colored granular variety, usually admixed with
         magnetic iron ore.
         [1913 Webster]

WordNet (r) 3.0 (2006):

sapphire
    adj 1: of something having the color of a blue sapphire;
           "sapphire eyes"
    n 1: a precious transparent stone of rich blue corundum valued
         as a gemstone
    2: a transparent piece of sapphire that has been cut and
       polished and is valued as a precious gem
    3: a light shade of blue [syn: azure, cerulean, sapphire,
       lazuline, sky-blue]

Moby Thesaurus II by Grady Ward, 1.0:

68 Moby Thesaurus words for "sapphire":
   adamant, agate, alexandrite, amethyst, aquamarine, azure,
   azure-blue, azure-colored, azurean, azured, azureous, beryl,
   beryl-blue, berylline, bloodstone, blue, bluish, brilliant,
   carbuncle, carnelian, cerulean, ceruleous, cerulescent, chalcedony,
   chrysoberyl, chrysolite, citrine, coral, cyanean, dark-blue,
   deep-blue, demantoid, diamond, emerald, garnet, girasol,
   harlequin opal, heliotrope, hyacinth, jade, jadestone, jargoon,
   jasper, lapis lazuli, light-blue, lightish-blue, livid, moonstone,
   morganite, onyx, opal, pavonian, pavonine, peacock-blue, peridot,
   plasma, rose quartz, ruby, sapphirine, sard, sardonyx, sky-blue,
   sky-colored, sky-dyed, spinel, spinel ruby, topaz, turquoise



Easton's 1897 Bible Dictionary:

Sapphire
   Associated with diamonds (Ex. 28:18) and emeralds (Ezek. 28:13);
   one of the stones in the high priest's breastplate. It is a
   precious stone of a sky-blue colour, probably the lapis lazuli,
   brought from Babylon. The throne of God is described as of the
   colour of a sapphire (Ex. 24:10; comp. Ezek. 1:26).