This is the 3317th most frequent Russian word.
патриотизм
Patriotism: Love and devotion to one's homeland.
The word "патриотизм" is used here as a noun to describe the social concept of devoting oneself emotionally to one's nation.
Патриотизм означает любовь к своей стране и готовность её защищать.
Patriotism means love for one's country and willingness to defend it.
In this sentence, "патриотизму" is the dative case of the noun "патриотизм," indicating the action being directed towards patriotism as a concept.
В школах учат детей патриотизму через изучение истории и культуры.
In schools, children are taught patriotism through the study of history and culture.
Here, "патриотизма" is in the genitive case of "патриотизм," representing possession, referring to features or qualities associated with patriotism.