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:
   1. Baseball. The nine players on a side, or the whole team.
   2. 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.

1. To the highest degree: dressed to the nines.

[Middle English, from Old English nigon.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.