n. & adj.
n. (pl. -ies) 1 the product of eight and ten. 2 a symbol for this (80, lxxx, LXXX). 3 (in pl.) the numbers from 80 to 89, esp. the years of a century or of a person's life.
adj. that amount to eighty. eighty-first, -second , etc. the ordinal numbers between eightieth and ninetieth. eighty-one, -two , etc. the cardinal numbers between eighty and ninety. eightieth adj. & n. eightyfold adj. & adv.
[ OE -eahtatig (as EIGHT, -TY(2)) ]