This is the 2562nd most frequent Arabic word.
الأردنية
"The Jordanian."
In this sentence, 'الأردنية' is used as an adjective referring to 'جامعة' (university), indicating its relation to Jordan as the country's national university.
الجامعة الأردنية هي أقدم جامعة في الأردن.
The University of Jordan is the oldest university in Jordan.
The word 'الأردنية' here acts as an adjective qualifying 'الطائرة' (airplane), specifying the nationality of the airplane as Jordanian.
الطائرة الأردنية هبطت في مطار لندن مساء الأمس.
The Jordanian aircraft landed at London airport yesterday evening.
In this example, 'الأردنية' is an adjective describing 'الشركة' (company), linking the company to its origin or registration in Jordan.