Do something in a jiffy means do it very fast, in an instant, that will be done in a very short time.Jiffy comes from two Latin words Sancti which means Holy and amen which means so is.Before, when the Christian prayers in latin, praying said at the end: In nomine Patris et Filii et Spiritus Sancti, amen (in the name of the father, of the son and of the Holy Spirit, amen). As I said very fast and at the same time is persignaba, the two last words almost were pronounced together. Sanctiamen, which later changed to snap.
