[ ok-tuh-juh-nair-ee-uhn ]
/ ˌɒk tə dʒəˈnɛər i ən /
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adjective Also oc·tog·e·nar·y [ok-toj-uh-ner-ee]. /ɒkˈtɒdʒ əˌnɛr i/.
of the age of 80 years.
between 80 and 90 years old.
a person who is between 80 and 90 years old.
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Origin of octogenarian

1805–15; <Latin octōgēnāri(us) comprising eighty, eighty years old (equivalent to octōgēn(ī) eighty each + -ārius-ary) + -an

OTHER WORDS FROM octogenarian

oc·to·ge·nar·i·an·ism, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What does octogenarian mean?

An octogenarian is someone in their 80s (80 to 89 years old), or someone who is 80 years old.

Octogenarian can also be used as an adjective to describe someone in their 80s, as in Our audience is mostly made up of octogenarian women, or things related to such a person, as in I have entered my octogenarian years. 

It’s one of several similar terms used to refer to a person of a certain age, including quadragenarian (40s), quinquagenarian (50s), sexagenarian (60s), septuagenarian (70s), and nonagenarian (90s).

Such words are more commonly used as people get older: quadragenarian and quinquagenarian are rarely used, but septuagenarian and octogenarian are more commonly used.

Another less common word for octogenarian is octogenary.

Example: Today is my last day as an octogenarian—tomorrow I begin my 90s!

Where does octogenarian come from?

The word octogenarian comes from the Latin word octōgēnāri(us), meaning “containing eighty” or “eighty years old,” from octōgēn(ī), meaning “eighty each.” The suffix -an is used to indicate a person (as seen in common words like pedestrian and historian).

It’s more common to refer to someone as a 80-year-old or describe them as in their 80s or 80-something than to call them an octogenarian. But octogenarian is used as a fancy or fun way of referring to someone of that age, including by octogenarians who apply it to themselves. As much fun as it is to say, it’s perhaps more often used in writing. It’s often used in the context of highlighting a person who’s doing something that may be surprising for their age, as in My octogenarian yoga instructor is way more flexible than I am.

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What are some other forms related to octogenarian?

  • octogenarianism (noun)

What are some synonyms for octogenarian?

  • octogenary
  • 80-year-old
  • eighty-year-old
  • 80-something
  • eighty-something

What are some words that share a root or word element with octogenarian

What are some words that often get used in discussing octogenarian?

How is octogenarian​ used in real life?

Octogenarian is often used to be fancy or funny when referring to 80-somethings.



Try using octogenarian!

Is octogenarian used correctly in the following sentence?

I can’t believe I’m nearing my octogenarian years—40 seems like yesterday.

How to use octogenarian in a sentence

British Dictionary definitions for octogenarian


less commonly octogenary (ɒkˈtɒdʒɪnərɪ)

/ (ˌɒktəʊdʒɪˈnɛərɪən) /

noun plural -narians or -naries
a person who is from 80 to 89 years old
of or relating to an octogenarian

Word Origin for octogenarian

C19: from Latin octōgēnārius containing eighty, from octōgēnī eighty each
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for octogenarian

[ ŏk′tə-jə-nârē-ən ]

Being between 80 and 90 years of age.
A person between 80 and 90 years of age.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.