Someone who embarasses (themselves and) their
country with rude,
stupid, or inappropriate behaviour, particularly in the
news or when travelling abroad. Can also refer to someone who is zealously patriotic; often a politician or sports reporter.
Do you ever notice that the flagwarts
always get tickets in the first three rows at the olympics?
Only a flagwart would wear a USA
jersey to a
Brazil/Argentina soccer match.
Did you see that flagwart on CNN? He's so wrapped in the flag, it almost strangled him.