Undercut, shown on a bowl cut
SIDES#1 to #2 one uniform length, no blend, hard line at the disconnect
NECKLINEBlocked square
UPKEEPRe-cut every 3 weeks

THE SIDES

Undercut

An undercut clips the sides to one uniform length with no fading at all, so the longer hair above meets it in a hard visible ledge. It is the opposite instinct to a fade: instead of hiding the transition, it makes the transition the whole point.

Also called disconnect, disconnected undercut, hard undercut.

See one on your face — free

Cut with a undercut

Every one of these is photographed at this fade. Tap any of them to see it on your own face.

Also works with one

These are cut with something else by default, so the photographs show that instead — but ask for a undercut and your barber will know exactly what you mean.

Questions

What is the difference between an undercut and a fade?
A fade is a gradient and an undercut is a step. An undercut is one guard all the way round with a deliberate hard line where the top begins; a fade blends that line away.
Does an undercut grow out badly?
It grows out more gracefully than a skin fade, because there is no gradient to blur — but the hard line softens after about three weeks and the shape goes with it.
EVERY FADE