Age by decade: A term designating someone's age by decade. For example, a septuagenarian refers to someone in his or her seventies (age 70 to 79). The prefix in such terms is always from the Latin. For example, the Latin septuageni = seventy. Denarian: Someone age 10 to 19. Vicenarian: Someone in his or her twenties. Tricenarian: Someone in his or her thirties. Quadragenarian: Someone in his or her forties. Quinquagenarian: Someone in his or her fifties. Sexagenarian: Someone in his or her sixties. Septuagenarian: Someone in his or her seventies. Octogenarian: Someone in his or her eighties. Nonagenarian: Someone in his or her nineties. Centenarian: Someone 100 or more. Supercentenarian: Someone 110 years old or more (no upper limit).

The terms denarian, vicenarian, tricenarian, and quadragenarian are not in common usage. The term supercentenarian was coined in 1991.