Ninety

Ninety

Number / Determiner / Pronoun / Noun · /ˈnaɪn.ti/

Definition

The number 90; nine times ten; representing a quantity of ninety units. Also: the nineties — the decade of years from 1990 to 1999, or the range of temperatures, ages, or scores from 90 to 99.

Origin

From Old English nigontig (ninety), from nigon (nine) + -tig (a group of ten; a decade), from Proto-Germanic *tehund (ten). The same -tig suffix giving twenty (twentiġ), thirty (þritiġ), forty (fēowertiġ), fifty (fiftiġ), sixty (sixtiġ), seventy (hundseofontiġ), eighty (hundeahtatig). The Proto-Germanic *tehund being related to Latin decem (ten) and Greek deka (ten) — all from Proto-Indo-European *déḱm̥t (ten). The ninety therefore being nine-decades — nine groups of ten.