Stubble
Very short facial hair, from a day's growth to a closely trimmed few millimetres.
Also: five o'clock shadow, designer stubble
Stubble is the short growth that appears within a day or so of shaving, sometimes called a five o'clock shadow. Deliberately kept stubble of a few millimetres, trimmed with a guard, became known as designer stubble in the 1980s, when pop stars and television actors wore it. It suits most face shapes. Barbers still tidy the cheek line and neckline so the stubble looks chosen rather than missed.