Glyph is a noun that refers to a small graphic symbol. 

The Greek word dulphe (dool FAY) is where our word of the day began life. Although it’s not a coincidence that our word of the day is contained in the word hieroglyphic, glyph is a broader word that may refer to any kind of graphic symbol. Here’s an example:

It’s a good thing I noticed that tiny glyph on my computer screen. If I hadn’t seen that tiny symbol, I might have overlooked the instruction to turn my computer off immediately.