Definition
Papillose describes a surface that's covered in papillae – those small, nipple-like or pimple-like projections. Think of it as a bumpy texture, but on a tiny scale. Unlike a smooth surface, a papillose one is rough and often plays a role in increasing surface area. This is common in plants and animals where absorption or adhesion is important. Essentially, it's the adjective form of having papillae.