NOUN (3)

1. a green transparent form of beryl; highly valued as a gemstone;

2. a transparent piece of emerald that has been cut and polished and is valued as a precious gem;

3. the green color of an emerald;

The Collaborative International Dictionary of English v.0.48:

Beryl \Ber"yl\ (b[e^]r"[i^]l), n. [F. b['e]ryl, OF. beril, L.
   beryllus, Gr. bh`ryllos, prob. fr. Skr. vai[dsdot][=u]rya.
   Cf. Brilliant.] (Min.)
   A mineral of great hardness, and, when transparent, of much
   beauty. It occurs in hexagonal prisms, commonly of a green or
   bluish green color, but also yellow, pink, and white. It is a
   silicate of aluminum and beryllium. The aquamarine is a
   transparent, sea-green variety used as a gem. The emerald
   is another variety highly prized in jewelry, and
   distinguished by its deep color, which is probably due to the
   presence of a little oxide of chromium.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Emerald \Em"er*ald\, n. [OE. emeraude, OF. esmeraude, esmeralde,
   F. ['e]meraude, L. smaragdus, fr. Gr. ?; cf. ?kr. marakata.]
   1. (Min.) A precious stone of a rich green color, a variety
      of beryl. See Beryl.
      [1913 Webster]

   2. (Print.) A kind of type, in size between minion and
      nonpare?l. It is used by English printers.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Emerald \Em"er*ald\, a.
   Of a rich green color, like that of the emerald. "Emerald
   meadows." --Byron.
   [1913 Webster]

   Emerald fish (Zo["o]l.), a fish of the Gulf of Mexico
      (Gobionellus oceanicus), remarkable for the brilliant
      green and blue color of the base of the tongue; -- whence
      the name; -- called also esmeralda.

   Emerald green, a very durable pigment, of a vivid light
      green color, made from the arseniate of copper; green
      bice; Scheele's green; -- also used adjectively; as,
      emerald green crystals.

   Emerald Isle, a name given to Ireland on account of the
      brightness of its verdure.

   Emerald spodumene, or Lithia emerald. (Min.) See
      Hiddenite.

   Emerald nickel. (Min.) See Zaratite.
      [1913 Webster]

WordNet (r) 3.0 (2006):

emerald
    n 1: a green transparent form of beryl; highly valued as a
         gemstone
    2: a transparent piece of emerald that has been cut and polished
       and is valued as a precious gem
    3: the green color of an emerald

The Free On-line Dictionary of Computing (19 January 2023):

Emerald

   An object-oriented distributed programming language and
   environment developed at the University of Washington in the
   early 1980s.  Emeral was the successor to EPL.  It is
   strongly typed and uses signatures and prototypes rather
   than inheritance.

   ["Distribution and Abstract Types in Emerald", A. Black et al,
   IEEE Trans Soft Eng SE-13(1):65-76 (Jan 1987)].

   (1994-11-09)