This is the 367th most frequent Arabic word.
البريطانية
"The British" or "British."
Here, 'البريطاني' is an adjective describing 'الأدب' (literature), specifying its cultural association with Britain.
الأدب البريطاني غني بالروائع الأدبية.
British literature is rich with literary masterpieces.
In this example, 'البريطانية' modifies the plural noun 'السيارات' (cars), indicating their British origin.
تعجبني السيارات البريطانية لجودتها.
I admire the British cars for their quality.
In this sentence, 'البريطانية' (translated as 'the British') is used as an adjective that describes the noun 'العاصمة' (the capital), identifying it as associated with Britain.