In an older sense, an
étagère is a
bookshelf that is often
narrow,
shallow, and sometimes
tapered to become narrower at the top. Fine
étagères are truly beautiful pieces of
furniture.
The more common meaning, at least in the US, is a bathroom rack that stands on legs on both sides of the the toilet. It typically has two to four shelves for towels and the like. In some places, this item is called a toilet topper. These étagères are not necessarily beautiful, but they add a minuscule footprint and are reasonably useful.