n. & adj.
n. (pl. -ies) 1 the product of nine and ten. 2 a symbol for this (90, xc, XC). 3 (in pl.) the numbers from 90 to 99, esp. the years of a century or of a person's life.
adj. that amount to ninety. ninety-first, -second , etc. the ordinal numbers between ninetieth and a hundredth. ninety-one, -two , etc. the cardinal numbers between ninety and a hundred. ninetieth adj. & n. ninetyfold adj. & adv.
[ OE nigontig ]