understructure

And I confess that at this close view of the understructure of a polygamous career, I was weak enough to feel scandalized.

Stan saw a Liberator smack into a bursting shell that exploded against her understructure.

The hair at the back of his neck lifted as his understructure raked across the hatch cover of the Jerry.

By the June of that year the understructure of the Pier was finished, and the rest was advancing with the speed of paper-hanging.