off-piste 
adjective & adverb Skiing
1Away from prepared ski runs: [as adjective]: off-piste slopes [as adverb]: heli-skiing is an expensive way of skiing off-piste...
- The huge adrenalin rush of surfing titanic waves such as this is often compared with other extreme sports such as skydiving and off-piste snowboarding and skiing.
- During the winter her main activities are off-piste skiing and ski touring.
- Initially I was just a holiday skier, but after we got our apartment here I took up off-piste skiing and ski-touring very seriously.
1.1So as to deviate from what is conventional, usual, or expected: [as adverb]: on this occasion I went off-piste and booked in at The Griffin, a place none of us had ever visited before. [as adjective]: an off-piste show...
- Some of us were so disappointed we decided to carry on meeting off-piste, at Riverside Books, if they'll have us.
- Motorists head 'off-piste' to evade cameras designed to catch cars nipping through a bus-only junction in Colchester.
- The high street is fine for seasonal sales but shopping off-piste will, more often than not, yield the best of the bargains all year round.