Is it ensure, insure, or assure?
In the Book of Genesis, a tower that the descendants of Noah built. They intended that the tower would reach up to heaven itself, increase their reputation, and make them like God. God prevented them from completing the tower by confusing their language so that they could no longer understand one another's speech. From that time forward, according to the Bible, the peoples of the Earth would be scattered, speaking different languages.
Note: “Babel” is confusion and noise.
the name given to the tower which the primitive fathers of our race built in the land of Shinar after the Deluge (Gen. 11:1-9). Their object in building this tower was probably that it might be seen as a rallying-point in the extensive plain of Shinar, to which they had emigrated from the uplands of Armenia, and so prevent their being scattered abroad. But God interposed and defeated their design by condounding their language, and hence the name Babel, meaning "confusion." In the Babylonian tablets there is an account of this event, and also of the creation and the deluge. (See CHALDEA.) The Temple of Belus, which is supposed to occupy its site, is described by the Greek historian Herodotus as a temple of great extent and magnificence, erected by the Babylonians for their god Belus. The treasures Nebuchadnezzar brought from Jerusalem were laid up in this temple (2 Chr. 36:7). The Birs Nimrud, at ancient Borsippa, about 7 miles south-west of Hillah, the modern town which occupies a part of the site of ancient Babylon, and 6 miles from the Euphrates, is an immense mass of broken and fire-blasted fragments, of about 2,300 feet in circumference, rising suddenly to the height of 235 feet above the desert-plain, and is with probability regarded as the ruins of the tower of Babel. This is "one of the most imposing ruins in the country." Others think it to be the ruins of the Temple of Belus.