The English have been enjoying pies for centuries. But where does their name come from? For such an apparently humble word, pie has a mysterious etymology.
pie pastry c.1300, from M.L. pie "meat or fish enclosed in pastry," perhaps related to M.L. pia "pie, pastry," also possibly connected with pica "magpie" (see pie (2)) on notion of the bird's habit of collecting miscellaneous objects. Not known outside English, except Gaelic pighe, which is from English. In the Middle Ages, a pie had many ingredients, a pastry but one. Fruit pies began to appear c.1600. Figurative sense of "something easy" is from 1889. Pie-eyed "drunk" is from 1904. Phrase pie in the sky is 1911, from Joe Hill's Wobbly parody of hymns. Pieman is not attested earlier than the nursery rhyme "Simple Simon" (c.1820). Pie chart is from 1922.
Is it perhaps related to the flat breads pitta and pide or Slavic pierogi? Is there a common PIE origin?