[annalex]

the root meaning of the word for baptism

You were probably told it's "immersion". See, however,

gifts and sacrifices are offered, which can not, as to the conscience, make him perfect that serveth, only in meats and in drinks, and divers washings, and justices of the flesh laid on them until the time of correction

(Hebrews 9:9-10)

The Greek for these diverse washings is "baptismois". It is not necessarily immersion; it is hard to imagine that all baptisms were by immersion in the arid Palestine. The Church however recommends immersion when practicable.

[Quix]

Uhhhhhhhhhhhhhhhhhhhhhhhhh . . .

From the time of the first Jewish worship rites' "brass sea"

immersion was a part of moving into righteousness.