Through which the world that then [existed] was deluged with water and perished. [Gen. 1:6-8; 7:11.]
whereby the world that then was, being overflowed with water, perished:
by which means the world that then was, being overflowed with water, perished:
And it was through these that the world of that time was flooded and destroyed.
By water, the former world then, having been inundated with water, perished.