Clue: Mountain-climbing fashion-conscious youth dressed in silver, perhaps (6)
Answer: PLATED
Explanation: Definition: dressed in silver, perhaps
 **Reversal of**(…-climbing, in a down clue) ALP(a high snow-capped mountain) + TED(short for "teddy boy"/a fashion-conscious youth in the 1950s and 1960s).
Defn: Dressed/covered with a thin layer of, say/perhaps, silver.