This is the 1628th most frequent Polish word.
narciarskich
"Narciarskich" means "skiing" or "ski-related" (adjectival form, plural genitive).
Here, 'narciarskie' is an adjective in its plural form, describing the noun 'buty' (boots).
Kupiliśmy nowe buty narciarskie.
We bought new ski boots.
In this example, 'narciarskie' modifies the noun 'ośrodki' (resorts), indicating their relation to skiing.
W Alpach są znakomite ośrodki narciarskie.
In the Alps, there are excellent ski resorts.
'Narciarskie' here functions as an adjective describing the noun 'ferie' (holidays), specifying them as ski-related.