What does eightieth mean?
"Eightieth" is the ordinal form of the number eighty, used to indicate position in a sequence (coming after the seventy-ninth) or to describe one of eighty equal divisions of a whole. It functions both as an adjective, as in "her eightieth birthday" or "the eightieth anniversary," and as a noun, as in "an eightieth of the total." In everyday usage it most often appears in connection with significant life milestones, since reaching one's eightieth year is widely celebrated across cultures as a mark of longevity and accomplishment. The word may be written out in formal contexts but is frequently abbreviated as "80th" in casual or space-constrained settings. Like other English ordinals, it derives from the Old English base word "eighty," combined with the ordinal suffix "-th." Its use is entirely standard in both British and American English, carrying no particular connotation beyond precision of order or proportion.
Coming next after the seventy-ninth in order; constituting the ordinal number corresponding to eighty.
"The eightieth page of the manuscript contained the author's signature."
A person or thing occupying the eightieth position, or one of eighty equal parts of a whole.
"Each heir received an eightieth of the inheritance."
Used when referring to multiple instances of an eightieth part.
"The recipe calls for three eightieths of a cup."
An eightieth birthday marks four full score years — the milestone Shakespeare called 'three score years and ten' plus a whole extra decade of living.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of eightieth
The word "eightieth" derives from Middle English, formed from "eighty" (itself from Old English "eahtatig") combined with the ordinal suffix "-th." It belongs to the same Germanic root family as "eight" and related number words such as "eighth" and "eighteen." Ordinal formations of this kind have existed throughout the recorded history of English.
How eightieth is actually used
Ordinals like eightieth are typically written with numerals in informal contexts (80th) and spelled out in formal writing. When referring to someone's age milestone, it commonly appears as 'his/her eightieth birthday' rather than 'the eightieth birthday.'
Easily confused with eightieth
Eighteen is the cardinal number 18, while eightieth is the ordinal form relating to the number eighty (80).