Off-piste
Any skiable terrain that lies outside marked, patrolled runs - including side-country, untracked bowls and backcountry.
Off-piste skiing ranges from a few turns in the trees beside a groomed trail to committing, avalanche-exposed backcountry descents. It is neither groomed nor avalanche-controlled, so carrying a transceiver, shovel and probe and understanding the day's avalanche forecast is essential.
In North America 'off-piste' is usually called backcountry or sidecountry, depending on how easy the access is from the resort.