From Longman Dictionary of Contemporary Englishoff-pisteˌoff-ˈpiste adjective not on the usual ski slopes off-piste skiing —off-piste adverb
Examples from the Corpus
off-piste• Once you fall into the rhythm of off-piste powder it is intoxicating.• Should we call this off-piste skiing?Origin off-piste (1900-2000) French piste “(ski) track”, from Old Italian pista, from pistare “to press down with the feet” 