Lead Room
The space left in front of a subject in the direction they face or move.
In depth
Lead room, sometimes called nose room, applies to gaze as much as to motion: a person looking left needs space on the left even if standing still, because the eye follows the gaze and needs somewhere for it to land. Denying it deliberately produces claustrophobia, which is a valid choice when the picture is about confinement.
Examples in practice
A portrait of someone looking off-frame is placed on the right so their gaze has two-thirds of the picture to travel into.