The word "nauseous" refers to a feeling of sickness or the sensation you experience when you are about to vomit. When someone feels nauseous, they may experience discomfort in their stomach, often accompanied by a strong aversion to food or certain smells. It can also describe something that causes this feeling, such as a bad smell or sight.
The word "nauseous" comes from the Latin word "nauseosus," which means "sick at the stomach." It is derived from "nausea," which also comes from the Greek word "nausea," meaning "sea sickness." The original references to the discomfort caused by being on the sea illustrate how even a pleasant voyage can lead to feelings of nausea.