The Collaborative International Dictionary of English v.0.48:

Myrrh \Myrrh\, n. [OE. mirre, OF. mirre, F. myrrhe, L. myrrha,
   murra, Gr. ?; cf. Ar. murr bitter, also myrrh, Heb. mar
   bitter.]
   A gum resin, usually of a yellowish brown or amber color, of
   an aromatic odor, and a bitter, slightly pungent taste. It is
   valued for its odor and for its medicinal properties. It
   exudes from the bark of a shrub of Abyssinia and Arabia, the
   Commiphora Myrrha (syn. Balsamodendron Myrrha) of the
   family Burseraceae, or from the Commiphora abyssinica.
   The myrrh of the Bible is supposed to have been partly the
   gum above named, and partly the exudation of species of
   Cistus, or rockrose.
   [1913 Webster]

   False myrrh. See the Note under Bdellium.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

bdellium \bdel"lium\, n. [L., fr. Gr. bde`llion; cf. Heb.
   b'dolakh bdellium (in sense 1).]
   1. An unidentified substance mentioned in the Bible (--Gen.
      ii. 12, and --Num. xi. 7), variously taken to be a gum, a
      precious stone, or pearls, or perhaps a kind of amber
      found in Arabia.
      [1913 Webster]

   2. A gum resin of reddish brown color, brought from India,
      Persia, and Africa.
      [1913 Webster]

   Note: Indian bdellium or false myrrh is an exudation from
         Balsamodendron Roxburghii. Other kinds are known as
         African bdellium, Sicilian bdellium, etc.
         [1913 Webster]