The Collaborative International Dictionary of English v.0.48:

Gem \Gem\, n. [OE. gemme precious stone, F. gemme, fr. L. gemma
   a precious stone, bud.]
   1. (Bot.) A bud.
      [1913 Webster]

            From the joints of thy prolific stem
            A swelling knot is raised called a gem. --Denham.
      [1913 Webster]

   2. A precious stone of any kind, as the ruby, emerald, topaz,
      sapphire, beryl, spinel, etc., especially when cut and
      polished for ornament; a jewel. --Milton.
      [1913 Webster]

   3. Anything of small size, or expressed within brief limits,
      which is regarded as a gem on account of its beauty or
      value, as a small picture, a verse of poetry, a witty or
      wise saying.
      [1913 Webster]

   Artificial gem, an imitation of a gem, made of glass
      colored with metallic oxide. Cf. Paste, and Strass.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Gem \Gem\ v. t. [imp. & p. p. Gemmed; p. pr. & vb. n.
   Gemming]
   1. To put forth in the form of buds. "Gemmed their blossoms."
      [R.] --Milton.
      [1913 Webster]

   2. To adorn with gems or precious stones.
      [1913 Webster]

   3. To embellish or adorn, as with gems; as, a foliage gemmed
      with dewdrops.
      [1913 Webster]

            England is . . . gemmed with castles and palaces.
                                                  --W. Irving.
      [1913 Webster]

WordNet (r) 3.0 (2006):

gem
    n 1: art highly prized for its beauty or perfection [syn: gem,
         treasure]
    2: a crystalline rock that can be cut and polished for jewelry;
       "he had the gem set in a ring for his wife"; "she had jewels
       made of all the rarest stones" [syn: gem, gemstone,
       stone]
    3: a person who is as brilliant and precious as a piece of
       jewelry [syn: jewel, gem]
    4: a sweet quick bread baked in a cup-shaped pan [syn: muffin,
       gem]
    5: a precious or semiprecious stone incorporated into a piece of
       jewelry [syn: jewel, gem, precious stone]

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

GEM

    One of the first commercially available
   GUIs.  Borrowing heavily from the Macintosh WIMP-style
   interface it was available for both the IBM compatible
   market (being packaged with Amstrad's original PC series)
   and more successfully for the Atari ST range.  The PC
   version was produced by Digital Research (more famous for
   DR-DOS, their MS-DOS clone), and was not developed very
   far.  The Atari version, however, continued to be developed
   until the early 1990s and the later versions supported 24-bit
   colour modes, full colour icons and a nice looking sculpted
   3D interface.

   (1997-01-10)