Meaning of the word "cost a fortune" in English

What does "cost a fortune" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

cost a fortune

US /kɔst ə ˈfɔrtʃən/
UK /kɒst ə ˈfɔːtʃən/

Idiom

to be very expensive

Example:
That new car must have cost a fortune.
Her diamond necklace cost a fortune.