1. A cross with diagonal bars of equal length; used in heraldry: A saltire is considered to be "ordinary" in the form of a cross with arms running diagonally from the dexter (right) chief to the sinister (left) base and from the sinister chief to the dexter base; such as, the St. Andrew's cross.

An "ordinary" saltire is used in heraldry to mean any of several conventional figures used on shields.

2. Etymology: an ordinary on a shield or flag like a St. Andrew's Cross, from Middle French (as written and spoken about 1400 to about 1600) saultoir; literally, "stirrup", from Medieval Latin saltatorium, neuter of Latin saltatorius, "pertaining to leaping"; from salire, "to leap". The connection between a stirrup and the diagonal cross is perhaps the two deltoid shapes that make up the cross.