Asymptomatic means without symptoms or not showing symptoms, such as of a disease or condition. This term is often used to describe someone who was tested for illness, but no symptoms were present. It also means not showing the existence of attributes or traits of a particular circumstance.
The word asymptomatic originated in American English in the 1930s as a combination of the prefix "a" and the word symptomatic. In medicine, another meaning of asymptomatic is not exhibiting or producing symptoms, such as in, "Johnny says he has the flu but his demeanor and his energy level appear asymptomatic of the flu."