What is "untiled"

Usage examples of "untiled".

The floor was bare and dusty: just an empty expanse of untiled concrete, stretching away between lines of square, unadorned pillars into shadows cast by a few, weak, overhead lamps.

The floor was bare and dusty: just an empty expanse of untiled concrete, stretching away between lines of square, unadorned pillars into shad­ows cast by a few, weak, overhead lamps.