means A reversal is a complete change to the opposite direction, position, or state — turning something around, undoing it, or flipping its outcome.

from From Latin 'reversus,' the past participle of 'revertere,' meaning to turn back — 're-' (back) plus 'vertere' (to turn), the same spinning root that gives us 'convert,' 'invert,' and 'vertigo.' English took in 'reverse' through Old French in the medieval period, and 'reversal' grew from it later as the noun for the act of turning the whole thing around.