девяносто

Etymology
, attested since 12th c., of unclear origin. With no parallels outside East Slavic—other Slavic branches point to —likely to be a late dialectal innovation (even more so considering that the higher decades are less frequent and more prone to innovations). Many explanations have been proposed and recently compared by Anikin, who cautiously supports *devę(t)no sъto 'nine-related hundred'.

Other hypotheses include, from (whence ) and  (whence ), with the ending influenced by. Compare 🇨🇬 and 🇨🇬.

Numeral

 * 1) ninety (90)