This is the 1575th most frequent Arabic word.
نووي
"نووي" means "nuclear."
In this sentence, "نووية" is used as an adjective to describe "أسلحة" (weapons) as being related to nuclear technology.
طورت العديد من الدول أسلحة نووية.
Many countries have developed nuclear weapons.
Here, "نووية" qualifies "الطاقة" (energy), meaning energy derived from nuclear processes.
الطاقة النووية تعتبر مصدرًا مهمًا للكهرباء.
Nuclear energy is considered an important source of electricity.
In this instance, "نووية" modifies "التكنولوجيا" (technology), indicating its relation to nuclear science and applications.