The term "brow" has multiple meanings depending on its context.
1) In a general sense, it refers to the upper part of the face between the eyes and above the nose. This area is also known as the forehead or brow ridge.
2) It can also refer to the furrowed lines that appear on someone's forehead when they are frowning or expressing anger, sadness, or worry - these are often referred to as "furrows" or "wrinkles".
3) In a more specific sense, it refers to the area above the eyes and between the hairline. This is known as the eyebrow ridge or brow line.