A citizen of one of the united States who loves his country.
Commonly, "love your country" is incorrectly interpreted as "support your country's government regardless of what it is doing". This is also, consequently, the type of person that people mistake a patriot as.
A true patriot loves his country to the extent that he will work to change it or point out what his country's government is doing wrong.
Most patriots wish to change the government to run the way the constitution describes it should.
Wow, Dave is against the Patriot Act, the Real ID act, and a whole bunch of unconstitutional laws. He must be a patriot.