A centenarian is a person who has reached the age of 100 years. Because life expectancies worldwide are below 100, the word centenarian is usually linked to longevity. The United States has the most centenarians, while Japan is second.
Much more rare is a supercentenarian, who is a person that has lived to be at least 110. Famous supercentenarians have included Harry Patch, who was the last surviving British soldier of the First World War trenches. He died on 25 July 2009 (aged 111). For the last seven days of his life he was Britain's oldest man. Henry Allingham, another First World War veteran, had died a week earlier (aged 113). [1]