A brow pencil is a cosmetic product used to define, shape, and fill in the eyebrows. It typically comes in a pencil form with a pointed tip and is available in a range of colors to match different hair colors.
The best drugstore brow pencil will be pigmented enough to provide good coverage, but not so pigmented that it looks unnatural. It should also be easy to apply and blend, and it should last all day without smudging or fading.