next after the eighty-ninth; being the ordinal number for 90.
being one of 90 equal parts.
a ninetieth part, especially of one (1/90).
the ninetieth member of a series.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use ninetieth in a sentence
Neither retirement nor a ninetieth birthday slowed his publication rate.
The same ideas precisely are found in the ninetieth hymn of the tenth book of the Rig-Veda.Myth, Ritual, and Religion, Vol. 1 | Andrew Lang
Mrs. Singleton is now in her ninetieth year but for some time past has been an invalid.Lyman's History of old Walla Walla County, Vol. 2 (of 2) | William Denison Lyman
Again, if he be perfectly formed on the forty-fifth day, he will move on the ninetieth and be born in the ninth month.The Works of Aristotle the Famous Philosopher | Anonymous
On the evening of his ninetieth birthday the old man went up to his wife and kissed her.The Empty House And Other Ghost Stories | Algernon Blackwood
It was the hundred and ninetieth mile-post just at her nose, and the dial read eight o'clock and fifty-five minutes to a second.The Nerve of Foley | Frank H. Spearman
British Dictionary definitions for ninetieth
being the ordinal number of ninety in numbering or counting order, position, time, etc. Often written: 90th
(as noun): the ninetieth in succession
one of 90 approximately equal parts of something
(as modifier): a ninetieth part
the fraction equal to one divided by 90 (1/90)
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