> Piątek (possibly means drinking day?)

The word means "the fifth day", from piąty (fifth) rather than pić (to drink).

Wtorek (Tuesday) comes from wtóry, meaning "second".

Środa (Wednesday) is from środa, meaning “middle”.

Sobota (Saturday) is from Hebrew שַׁבָּת‎ (šabbāṯ), meaning the Sabbath.