1. The cardinal number equal to 8 + 1.
2. The ninth in a set or sequence.
3. Something having nine parts, units, or members.
4. Games A playing card marked with nine pips.
5. A set of nine persons or things, especially:
a. Baseball The nine players on a side, or the whole team.
b. Nine Greek Mythology The nine Muses.
6. A size, as in clothing or shoes, designated as nine.
7. Sports The first or second 9 holes of an 18-hole golf course.
to the nines Informal
To the highest degree: dressed to the nines.
[Middle English, from Old English nigon; see new in the Appendix of Indo-European roots.]
nine adj. & pron.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2017 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.
American Heritage Dictionary Products
The American Heritage Dictionary, 5th Edition
The American Heritage Dictionary of Idioms
The American Heritage Roget's Thesaurus
Curious George's Dictionary
The American Heritage Children's Dictionary
The American Heritage Dictionary of Indo-European Roots
The American Heritage Student Grammar Dictionary
The American Heritage Desk Dictionary + Thesaurus
The American Heritage Science Dictionary
The American Heritage Dictionary of Business Terms
The American Heritage Student Dictionary
The American Heritage Essential Student Thesaurus