This is the 895th most frequent Hungarian word.
pénteki
The Hungarian word "pénteki" means "Friday's" or "relating to Friday."
"Pénteki" is an adjective here, modifying "programok" (activities), describing that they belong or relate to Friday.
A pénteki programok mindig szórakoztatóak.
The Friday activities are always entertaining.
Here, "pénteki" specifies "találkozóra" (meeting), meaning it occurred last Friday.
Emlékszel a múlt pénteki találkozóra?
Do you remember last Friday's meeting?
In this instance, "pénteki" is used adjectivally to describe "napra" (day), indicating it is the day Friday.