This is the 977th most frequent Romanian word.
roșu
The Romanian word "roșu" means "red" in English.
In this sentence, "roșu" is used as an adjective describing the noun "mărul" (the apple). It specifies the color of the apple.
Mărul este roșu.
The apple is red.
Here, "roșu" is once again an adjective, used to specify the color of the item of clothing (tricou - shirt). It agrees in gender and form with the noun.
El poartă un tricou roșu.
He is wearing a red shirt.
In this sentence, "Roșu" is used as a noun, representing the concept of the color red itself.