国 is pronounced guó in the second tone. It means country, state or nation.
家 is pronounced jiā in the first tone. It means family, home or household.
The two words 国 家 mean country, state or nation. This reinforces the Chinese belief that a nation is one big family.
Měiguó shì yīgè mínzhǔ guójiā.
The United States of America is a democratic country.