■ cardinal number ( plural eighties ) equivalent to the product of eight and ten; ten less than ninety; 80. (Roman numeral: lxxx or LXXX .)
Derivatives
eightieth ordinal number .
~fold adjective & adverb
Origin
OE hunde(a)htatig , from hund (of uncertain origin) + e(a)hta 'eight' + -tig (see -ty 2 ).