next after the seventy-ninth; being the ordinal number for 80.
being one of 80 equal parts.
an eightieth part, especially of one (1/80).
the eightieth member of a series.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use eightieth in a sentence
He lived to be ninety years old, and produced the most beautiful of his tragedies in his eightieth year, the "Oedipus at Colonus."Beacon Lights of History, Volume I | John Lord
Mlle. Clairon died on January 31, 1803, six days after completing her eightieth year.Queens of the French Stage | H. Noel Williams
So active did he continue to the end of his days, that on his eightieth birthday he climbed an oak in my company.Wanderings in South America | Charles Waterton
Since that date he has lived retired in Hutchinson, where he still makes his home, being now in the eightieth year of his age.Lyman's History of old Walla Walla County, Vol. 2 (of 2) | William Denison Lyman
None of us are, you know, when we pass the eightieth milestone!Cursed | George Allan England
British Dictionary definitions for eightieth
being the ordinal number of eighty in numbering or counting order, position, time, etc: often written 80th
(as noun): the eightieth in succession
one of 80 approximately equal parts of something
(as modifier): an eightieth part
the fraction equal to one divided by 80 (1/80)
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