The most common and most likely answer to this crossword clue is the 5 letter word SKIER
I've seen this crossword clue in Financial Times
S
K
I
E
R
More clues leading to the result SKIER
- Winter sportsperson less safe leaving Rhode Island
- Winter sportsman or cricketer hitting high ball
- Sporty sort to steal tuppence from captain?
- Risk sliding around close to crevasse, for one going down mountain
- Work-shy person —but not very — is one on a downward slope
- Unexpected risk limits English winter sportsman
- Winter sportsman very quietly easing away from captain
- Maybe sportsman’s captain not very quiet
- One going downhill fast in winter?
- Newscast from comedian Frank: he’s possibly going downhill quickly
Buddy explains!

The straight part
We know that "One going downhill fast in winter" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one going downhill fast in winter = skier.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.
What does SKIER mean?
SKIER noun- One who skis.
- A ball hit high in the air, often leading to a catch.