This is the 832nd most frequent Hungarian word.
karácsony
"Karácsony" means "Christmas" in English.
Here, 'karácsony' refers to the holiday of Christmas as a specific time of the year.
A karácsonyt mindig a családommal töltöm.
I always spend Christmas with my family.
In this instance, 'karácsonyi' is an adjective derived from 'karácsony', used to describe the market as being related to Christmas.
A karácsonyi vásár tele van szép ajándékokkal.
The Christmas market is full of beautiful gifts.
Here, 'karácsony' represents the general spirit or atmosphere associated with Christmas time.