The Collaborative International Dictionary of English v.0.48:

Peshito \Pe*shit"o\, Peshitto \Pe*shit"to\, n. [Syriac
   pesh[^i]t[^a] simple.]
   The earliest Syriac version of the Old Testament, translated
   from Hebrew; also, the incomplete Syriac version of the New
   Testament. [Written also peschito.]
   [1913 Webster]