This is the 16045th most frequent Russian word.
пятничной
"Пятничной" means "Friday's" or "related to Friday" in English.
The word 'пятничной' is used as an adjective in the genitive feminine singular form, describing 'работы' (work) as pertaining to Friday.
Мы договорились встретиться после пятничной работы.
We agreed to meet after Friday's work.
The word 'пятничной' serves as an adjective modifying 'вечеринке' (party), indicating the specific day of occurrence, Friday.
Он готовится к пятничной вечеринке.
He is preparing for the Friday party.
Here, 'пятничной' functions as an attribute of 'радости' (joy), emphasizing the special quality associated with Fridays.