This is the 256th most frequent Polish word.
duże
"Duże" means "big" or "large" in English.
In this sentence, 'duże' is used as an adjective describing the noun 'jabłko' (apple). It is in the neuter gender singular form, matching the grammatical gender and number of the noun it modifies.
Mam duże jabłko.
I have a big apple.
Here, 'duże' functions as an adjective but is in the plural form, modifying the noun 'marzenia' (dreams). It agrees in gender, number, and case with the plural noun it describes.
Te dzieci mają duże marzenia.
These children have big dreams.
In this context, 'duże' is an adjective qualifying 'miasto' (city), which is a neuter singular noun, and the word 'duże' matches its grammatical attributes.