1382, as if it were the pp. of a verb form of M.E. noun pie
"magpie" (see pie
(2)), in ref. to the bird's black and white plumage. Earliest use is in reference to the pyed freres,
an order of friars who wore black and white. Also in pied piper
(1845, in Browning's poem based on the Ger. legend; used allusively from 1942).