The DICT Development Group

  Harlequin \Har"le*quin\ (h[aum]r"l[-e]*k[i^]n or -kw[i^]n), n.
     [F. arlequin, formerly written also harlequin (cf. It,
     arlecchino), prob. fr. OF. hierlekin, hellequin, goblin, elf,
     which is prob. of German or Dutch origin; cf. D. hel hell.
     Cf. Hell, Kin.]
     A buffoon, dressed in party-colored clothes, who plays
     tricks, often without speaking, to divert the bystanders or
     an audience; a merry-andrew; originally, a droll rogue of
     Italian comedy. --Percy Smith.
     [1913 Webster]
  
           As dumb harlequin is exhibited in our theaters.
                                                    --Johnson.
     [1913 Webster]
  
     Harlequin bat (Zool.), an Indian bat ({Scotophilus
        ornatus), curiously variegated with white spots.
  
     Harlequin beetle (Zool.), a very large South American
        beetle ({Acrocinus longimanus) having very long legs and
        antenn[ae]. The elytra are curiously marked with red,
        black, and gray.
  
     Harlequin cabbage bug. (Zool.) See Calicoback.
  
     Harlequin caterpillar. (Zool.), the larva of an American
        bombycid moth ({Euch[ae]tes egle) which is covered with
        black, white, yellow, and orange tufts of hair.
  
     Harlequin duck (Zool.), a North American duck
        ({Histrionicus histrionicus). The male is dark ash,
        curiously streaked with white.
  
     Harlequin moth. (Zool.) See Magpie Moth.
  
     Harlequin opal. See Opal.
  
     Harlequin snake (Zool.), See harlequin snake in the
        vocabulary.
        [1913 Webster]

  Opal \O"pal\, n. [L. opalus: cf. Gr. ?, Skr. upala a rock,
     stone, precious stone: cf. F. opale.] (Min.)
     A mineral consisting, like quartz, of silica, but inferior to
     quartz in hardness and specific gravity.
     [1913 Webster]
  
     Note: The precious opal presents a peculiar play of colors
           of delicate tints, and is highly esteemed as a gem. One
           kind, with a varied play of color in a reddish ground,
           is called the harlequin opal. The fire opal has
           colors like the red and yellow of flame. Common opal
           has a milky appearance. Menilite is a brown impure
           variety, occurring in concretions at Menilmontant, near
           Paris. Other varieties are cacholong, girasol,
           hyalite, and geyserite.
           [1913 Webster]

  harlequin opal
      n 1: a reddish opal with small patches of brilliant color