When you're nauseated, you're queasy, or you feel like you might vomit. If you have the flu, you'll probably spend a day or two feeling nauseated.
Queasy. Sick to your stomach. Barfy. All of these describe the uncomfortable feeling of being nauseated. Riding on a roller coaster three times in a row could make you feel nauseated, and if you sat down and ate an entire three-layer birthday cake by yourself, you'd definitely be nauseated by the time you finished. The Latin root word nausea originally described seasickness.