Pronunciation: (ā'tē), [key]
—n., pl. eight•ies,
1. a cardinal number, ten times eight.
2. a symbol for this number, as 80 or LXXX.
3. a set of this many persons or things.
4. eighties,the numbers, years, degrees, or the like, from 80 through 89, as in referring to numbered streets, indicating the years of a lifetime or of a century, or degrees of temperature.
amounting to 80 in number.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.