This is the 12483rd most frequent Polish word.
najdroższym
"Najdroższym" means "the most expensive" in English.
The word 'najdroższym' is used as a superlative adjective, meaning 'the most expensive', modifying the noun 'city'.
Warszawa jest najdroższym miastem w Polsce.
Warsaw is the most expensive city in Poland.
The term 'najdroższym' describes the couch as the most expensive item in comparison to others available in the store.
Kupiliśmy najdroższym kanapę w sklepie.
We bought the most expensive couch in the store.
Here, 'najdroższym' is used figuratively to mean 'most precious', modifying the noun 'treasure'.