1. eighty-ninth - Noun
2. eighty-ninth - Adjective
eighty-ninth
The ordinal form of the number eighty-nine, describing a person or thing in position number 89 of a sequence.
The answer appears on the eighty-ninth page of the book.
She finished eighty-ninth in the race.
eighty-ninth (plural eighty-ninths)
One of eighty-nine equal parts of a whole.
An eighty-ninth of 1780 is 20.