to swallow: to take something wholly in and make it disappear, from gulping food down to engulfing and destroying.
At its center this word is about something being taken completely in and gone. The plainest picture is a mouth and a throat: a great fish swallows Jonah, hungry cattle and ears of grain swallow up the others in Pharaoh's dream, Aaron's staff swallows the staffs of Egypt's magicians. From there it widens to the ground itself opening its mouth, the earth swallowing Korah and his followers so that they vanish alive.
The same image carries a heavier weight when the thing swallowed is a person, a people, or a city. To swallow someone up is to consume and ruin them past recovery, the way a grave or a flood takes a life and closes over it. Enemies plot to swallow up the helpless; God himself is said to swallow up death forever, and in Lamentations to have swallowed up Zion. The English Bibles often render this side of the word as devour, destroy, or engulf.
A smaller group of uses leans toward confusion and reeling, where what is swallowed is a plan, a tongue, or a person's wits: a counsel undone, speech thrown into disorder, sailors staggering at sea. Some scholars trace these to a separate ancient root that only looked the same, while others read them as the same word pushed to its limit, the mind or the plan swallowed up and lost. Either way the picture holds together: something whole is taken in and does not come back.