This is the 994th most frequent Czech word.
vánoční
"Vánoční" means "Christmas" or "relating to Christmas" in English.
In this sentence, 'vánoční' describes the market ('trh'), associating it with the Christmas season.
Vánoční trh začíná tento pátek.
The Christmas market starts this Friday.
Here, 'vánoční' qualifies the presents ('dárky'), indicating they are intended for the Christmas holiday.
Koupili jsme vánoční dárky pro celou rodinu.
We bought Christmas presents for the whole family.
The word 'vánoční' (Christmas) is used here as an adjective describing the tree ('stromeček'), linking it to the festive tradition.