Someone who loves Portugal and is decendent of portuguese. They eat things like sopa de feijao or bacalhau a braz. They speak portuguese and have a valid portuguese passport.
Or Someone who is from Portugal. They were born in portugal aswell as many other generations of their grand-parents and family. They may be living in or outside of portugal but they keep their culture alive wherever they go.
I am portuguese that is why I can say to you" Sou portuguese por amor da minha patria"