Definition of Age by decade

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.