Formal:
* Etagere: A French word for a type of open shelving unit, often with multiple tiers.
* Credenza: Typically a low, wide cabinet with shelves, often used for displaying decorative objects.
* Display Cabinet: A cabinet with glass doors and shelves, used for showcasing items.
* Curio Cabinet: A cabinet, usually with glass doors, used for displaying collectibles.
Informal:
* Shelves: A generic term for shelves, suitable for informal contexts.
* Bookcases: If the shelves are designed to hold books.
* Open Shelving: Emphasizes that the shelves are not enclosed.
* Display Shelves: A straightforward and common term.
* Floating Shelves: If the shelves are attached directly to the wall without visible supports.
Descriptive:
* Ornate shelves: If the shelves have decorative details.
* Rustic shelves: If the shelves are made from natural materials and have a simple, unfinished look.
* Modern shelves: If the shelves have a contemporary design.
Other:
* Knick-knack shelves: A humorous term for shelves that hold small, decorative items.
* Treasure shelves: Implies that the shelves hold valuable or treasured items.
The best word to use will depend on the specific style and context of your writing or conversation.