/ay"tee/ , n. , pl. eighties , adj.
n.
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.
adj.
5. amounting to 80 in number.
[ bef. 850; ME eighteti, OE eahtatig. See EIGHT, -TY 1 ]