har·le·quin / ˈhärlək(w)ən/ • n. 1. (Harlequin) a mute character in traditional pantomime, typically masked and dressed in a diamond-patterned costume. ∎  hist. a stock comic character in Italian commedia dell'arte. 2. (also harlequin duck) a small duck (Histrionicus histrionicus) of fast-flowing streams around the Arctic and North Pacific, the male having mainly gray-blue plumage with bold white markings.• adj. in varied colors; variegated.

Harlequin a mute character in traditional pantomime, typically masked and dressed in a diamond-patterned costume, in the Italian commedia dell' arte the lover of Columbine.

The name (recorded from the 16th century) comes from obsolete French, from earlier Herlequin (or Hellequin), the name of the leader of a legendary troop of demon horsemen; perhaps ultimately related to Old English Herla cyning ‘King Herla’, a mythical figure sometimes identified with Woden.
harlequinade the section of a traditional pantomime in which Harlequin played a leading role. It originated in the Italian commedia dell'arte as a sequence of narrative dances, but became a mere epilogue to the presentation of a fairy tale, which eventually displaced it altogether.

harlequin character (associated with Columbine) in It. comedy and Eng. pantomime (clothed in variegated costume, whence the application of the word to animals with variegated coat, plumage, etc.). XVI. — F. †harlequin (mod. arlequin, after It. arlecchino), later var. of Herlequin leader of the Wild Host or troop of demon horsemen riding by night, which has been plausibly referred (as if for *Herlechingi) to OE. Herla cyning king Herla, whose characteristics have been identified with those of Woden.

harlequin English name derived from the character Arlecchino of the Commedia dell'arte, who was a quick-witted, unscrupulous serving man. A harlequin nowadays appears in pantomine and comedy as a mute jester, dressed in diamond-patterned, multi-coloured tights.