piebaldPronunciation: /ˈpʌɪbɔːld/Definition of piebald adjective (of a horse) having irregular patches of two colours, typically black and white. noun a piebald horse. Origin: late 16th century: from pie2 (because of the magpie's black-and-white plumage) + bald (in the obsolete sense 'streaked with white')piebald in other Oxford dictionaries Definition of piebald in the US English dictionary