“Centenary” can be used as both an adjective and a noun. It comes from the Latin words “centenarius” and “centum,” which mean “denoting a hundred” and “a hundred,” respectively. Places or events are not the only subjects of a hundred-year anniversary — people celebrating their 100th birthday are also observing a centenary. According to the Pew Research Center, it’s estimated that the number of people celebrating a centenary will more than quadruple over the next few decades. Around 101,000 Americans will turn 100 in 2024, and that number is estimated to be around 422,000 in 2054.