This is the 6596th most frequent Arabic word.
الامريكي
"The American."
Here, 'الامريكي' is used as an adjective to describe the nationality of the man.
يعيش الرجل الامريكي في نيويورك.
The American man lives in New York.
In this sentence, 'الامريكية' is a feminine adjective describing the culture.
الكثير من الناس يحبون الثقافة الامريكية.
Many people love American culture.
In this context, 'الامريكية' is part of a proper noun referring to a specific educational institution.