ninetieth

[ nahyn-tee-ith ]

/ ˈnaɪn ti ɪθ /

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.

Origin of ninetieth

before 1100; Middle English nyntithe, Old English nigenteotha. See ninety, -eth²

Neither retirement nor a ninetieth birthday slowed his publication rate.

The Best of Brit Lit |Peter Stothard |August 27, 2010 |DAILY BEAST
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
I examined all my hives on the eighty-third day, and on the ninetieth day I found four swarms dead.

A Manual or an Easy Method of Managing Bees |John M. Weeks
It receives from the sun about one ninetieth of the light and heat that we get.

Other Worlds |Garrett P. Serviss

When we reached this point the One Hundred and Ninetieth was thrown forward in skirmish line.

In The Ranks |R. E. McBride
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

ninetieth

/ (ˈnaɪntɪɪθ) /

(usually prenominal)

being the ordinal number of ninety in numbering or counting order, position, time, etc. Often written: 90th
(as noun)the ninetieth in succession

the fraction equal to one divided by 90 (1/90)