harlequin:
(plural: ‘harlequins‘)

(a young boy with harlequin make-up)
a person who wears special brightly coloured clothes, usually with a diamond pattern, and plays (acts) amusing character in traditional plays;
a clown;
a buffoon,

a harlequin in diamond shaped colourful costume
Harlequins, along with the court jesters, used to be a part of the royal courts for the entertainment of the courtiers.
With his brightly coloured and tight clothes, Charlie is often called the harlequin by his friends.
Though they don’t wear the same kind of colourful diamond patterned tight fitting clothes, the stand-in comedians prefer to call themselves ‘harlequins’ just of the old times’ sake.
Apart from the traditional human harlequins who have made the world lighter with their comedy, there are some non-human and non-comic harlequins, animals with colourful patchy design on them; some of them are: harlequin duck, harlequin ladybird, harlequin shrimp, harlequin dog and harlequin ghost pipefish.

(a harlequin dog)
‘Harlequin’, as an adjective, is used to refer to any design with different colours and in irregular shapes, commonly in diamond shapes. For an article about the harlequin duck, please click here. The word ‘Harlequin’ is often found in the names of hotels, clubs, sports clubs and other business establishments. For a popular football club by this name, please click here.
