Someone who is from the United States of America, hence the "USA," in USAian.
Instead of referring to them as American, since America is made up of two (or one continent depending on a country's continent model) continents: North America, which ends at the isthmus of Panama. And South America, which starts in Punta Gallinas, Colombia.
Everyone from the Americas is American, just like everyone from any country in Europe is European. Therefore, the term "USAsian" is more specific to people from the United States.
Alex: Cool, me too! What part? I'm from Mexico.
John: Oh, I meant, I'm from America, as in The United States.
Alyssa: America is the entire continent, silly. I'm from Canada, so we're ALL American. You're USAsian.
A citizen of USA, United States of America. As an American would be confused with people of South and Central Americas as well as Canadians.
Plural: USAians
And also: USAese like Chinese, Japanese
USAians tried to introduce democracy to Iraq and ended up reducing the population there by 1.5 million for good and over 4 million left the country.
Anti imperialist word to describe people who live in the USA in order to replace the term americans, since everyone who lives in the continent (not country!) America are americans and it is not a word exclusive for usanians.
A bunch of usanians were causing uproar on the internet.
You are at a bar in Shanghai and hear familiar language in a smattering of accents coming from a nearby table. You walk up to the table and greet the folks there, and they ask you to sit down. The next question they ask you, after "What are you drinking?" is "So...Canuck or USAnian?"