Dictionary.com's Word of the Year is...
chickenpox or chicken pox
An acute contagious disease, primarily of children, that is caused by the varicella-zoster virus and characterized by skin eruptions, slight fever, and malaise. Also called varicella.
A highly contagious infectious disease, usually of children, caused by the varicella-zoster virus of the genus Varicellavirus. The infection is characterized by fever, and itching skin blisters that start on the trunk of the body and spread to the extremities. Also called varicella.