What does eighty mean?
Eighty is the cardinal number equal to eight tens, written as 80 in figures. It functions primarily as a noun or determiner-like numeral, counting people, things, money, and units of measure, as in 'eighty guests' or 'an eighty-mile drive.' Beyond pure arithmetic, English uses it idiomatically: a person who is 'in her eighties' is aged between 80 and 89, while 'the Eighties' commonly denotes the decade 1980–1989, evoking particular fashions, music, and politics. The word derives from Old English 'eahtatig,' combining 'eahta' (eight) with the '-tig' suffix meaning a group of ten, making it a direct descendant of ancient Germanic counting. Its rhyming kinship with other round-number words like forty, thirty, and twenty reflects that shared structure. Whether describing a milestone birthday, a sum of money, or a nostalgic decade, eighty is an everyday workhorse of English numeracy.
The cardinal number equal to eight times ten; the figure 80.
"The hall seats eighty for dinner."
A person's age of eighty years; also, the range of ages from eighty to eighty-nine when used in the phrase 'one's eighties.'
"He remained sharp well into his eighties."
In the age-range sense, the word takes the plural form 'eighties' within the fixed phrase 'in one's eighties.'
The plural 'eighties' appears chiefly in two fixed uses: decades of years (especially the 1980s) and ranges of age (in one's eighties). The plain numeral 'eighty' itself does not take a plural when simply counting.
"Vinyl records made a big comeback during the eighties."
In English, 'eighty' breaks the pattern — most European languages say 'four twenties' for it, a habit French still keeps today with 'quatre-vingts.'
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of eighty
Eighty comes from Old English 'eahtatig,' formed from 'eahta' (eight) plus '-tig,' a suffix meaning a group or multiple of ten. It shares this transparent Germanic construction with all the other tens in English, from twenty through ninety, and is cognate with German 'achtzig' and Dutch 'tachtig.' Notably, many neighboring European languages instead express eighty as four twenties — French 'quatre-vingts' preserves an old vigesimal system that English never adopted, making 'eighty' one of the more regular number words in the language.
How eighty is actually used
As a numeral, 'eighty' is typically written as a word in formal prose and as '80' in technical, statistical, or informal contexts. In its decade sense ('the eighties'), it commonly refers to the 1980s and usually takes the definite article.
Easily confused with eighty
'Eighty' is the cardinal number 80, while 'eighteenth' is the ordinal form referring to position number 18.