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.
Phrases and idioms:
ninety-first, -second , etc. the ordinal numbers between ninetieth and a hundredth. ninety-one, -two , etc. the cardinal numbers between ninety and a hundred.
Derivatives:
ninetieth adj. & n. ninetyfold adj. & adv.
Etymology: OE nigontig