mat·zo also mat·zoh 
(mätsə, -sō′, -sô′, mät-sä)
(mätsə, -sō′, -sô′, mät-sä)n. pl. mat·zos also mat·zohs (mätsəz, -sōs′) or mat·zot or mat·zoth (mät-sôt)
A flat, usually brittle piece of unleavened bread, eaten especially during Passover.
[Yiddish matse, from Hebrew maṣṣâ; see m in the Appendix of Semitic roots.]