1. Of or pertaining to the United States of America
2. A Citizen of the United States of America
A sometimes pejorative term coined in recent years on various internet discussion boards. Meant to resolve the ambiguous nature of the terms "North American," which could be taken to refer to Canada or the United States, and "American," which could be taken to refer to North America, South America, or the United States.
1. I'm not a fan of all of this USian war-mongering.
2. You'd never understand universal healthcare--you're a USian.