It comes from the Greek word bapto, which means to dip. Thus baptism is a plunging or dunking of the subject beneath the waters. This may be going too far, though. He received the rite of baptism from a deacon and evangelist from the church in Jerusalem, even though he was headed away from Jerusalem. Acts records others who received the rite of baptism apart from any apparent connection to a church, too.
Baptism is to be by dunking or dipping the person into water, that is, a submersion or immersion.
A person thus submerged in the name of the the Lord has received scriptural baptism, as plunging beneath the water is the only mode of baptism recognized in the New Testament. Sprinkling and pouring, also called affusion, are not legitimate modes of baptism at all. Nor is baptism legitimate unless the person immersed has receive salvation and has obtained the benefit of justification. Sacramentarian baptism is not supported by the New Testament, credobaptism is. They hold that it is faith plus baptism that saves an individual, and base this on a few verses of Scripture which they have misunderstood.