labonza (n.)

late 14c. paunce, "the human belly," from Old French pance (Old North French panche) "belly, stomach," from Latin panticem (nominative pantex) "belly, bowels" (source also of Spanish panza, Italian pancia); which is possibly related to panus "swelling" (see panic (n.2)). Earlier in English it meant "plate or mail armor worn to protect the belly" (early 14c.).