This is the 129th most frequent Hebrew word.
נוסף
Added; additional.
The word "נוסף" is used here as an adjective to mean "additional" or "another", describing the noun "ילד".
במשפחה שלי נולד ילד נוסף השנה.
In my family, an additional child was born this year.
In this context, "בנוסף" is an adverbial conjunction meaning "in addition to", connecting the clause about the advantages to the additional benefit.
בנוסף לכל היתרונות של המוצר, הוא גם נוח לשימוש.
In addition to all the advantages of the product, it is also easy to use.
Here, "נוסף" is an adjective used to describe "מעיל", highlighting its meaning as "extra" or "additional".