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.
