The most common and most likely answer to this crossword clue is the 9 letter word OFF-PISTE
I've seen this crossword clue in The Times
O
F
F
-
P
I
S
T
E
More clues leading to the result OFF-PISTE
- On a slippery slope, taking unnecessary risks?
- Wrong step: I moved on less common routes
- Briefly propose accepting tips about avoiding experienced skiers?
- Fife’s top resort, where snow’s deeper
- Avoiding regular runs, softie worked out with slices of frozen pizza
- It suggests I step on virgin snow
- Where skiers venture in spite of fine, stupidly
- Street covered in rotten food, aside from the majority going downhill
- Somehow I stop before edge of precipice catching two females on dangerous slope?
- Old fellow, confounded pest if not on-topic
Buddy explains!

The straight part
We know that "on less common routes" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case on less common routes = off-piste.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
Crossword Answer definitions
OFF-PISTE adjective- (of snow or ski-runs) Not specially prepared or designated for skiing, hence viewed as more exciting but also more dangerous.
- Deviating from what is seen as correct, usual or conventional.
- In off-piste locations.