What does eighth mean?
"Eighth" is the ordinal form of the number eight, indicating position eight in a sequence — the eighth day of the month, the eighth chapter of a book, or the eighth runner to cross the finish line. It also functions as a noun denoting one of eight equal parts of a whole, as when a pie is cut into eighths, or a measure such as an eighth of a mile. In American musical terminology, an "eighth note" is a note lasting half as long as a quarter note, though British English prefers the term "quaver." The word derives from Old English "eahtoþa," built on the root of "eight," which itself traces back through Germanic languages to the Indo-European root "oktō(u)," shared with Latin-derived words like "octave" and "octagon." Spelled with an uncommon consonant cluster, it is pronounced /eɪtθ/. Whether marking rank, dividing portions, or measuring musical time, "eighth" is a versatile and precise numerical term used across everyday, mathematical, and musical contexts.
Coming next after the seventh and before the ninth in a sequence; 8th.
"Her office is on the eighth floor of the building."
Usually preceded by "the" or a possessive.
One of eight equal parts of a whole; also, in music, a note with half the value of a quarter note (US usage).
"Three-eighths of the respondents favored the proposal."
Often written as a fraction (1/8); in music, British English uses "quaver" instead.
In the eighth place or position; lastly in a list of eight items.
"First, prepare the dough; second, roll it out; ... eighth, bake at 350 degrees."
Used when referring to multiple eighth-parts, especially in fractions (e.g., three-eighths, five-eighths).
"The recipe calls for three-eighths of a cup of sugar."
The "th" in "eighth" is one of the rarest letter combinations in English — and it's silent in the spelling but not the sound: /eɪtθ/ packs two consonant sounds into that final cluster.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of eighth
"Eighth" descends from Old English "eahtoþa," formed from "eahta" (eight), which traces back through Proto-Germanic to the Proto-Indo-European root *oktō(u). This same ancient root gave rise to Latin "octavus" (eighth) and Greek "oktō," making "octave," "octagon," and "octet" distant cousins of the word. The modern spelling with the "-th" suffix for ordinals was standardized in Middle English, retaining the full consonant ending inherited from the older forms.
Related word forms
How eighth is actually used
As an ordinal, "eighth" typically takes the definite article ("the eighth day"). In British English, "quaver" is the standard term for what Americans call an "eighth note." The fraction sense often appears with "an" or "one": "an eighth of a mile." Note the unusual spelling with both "h" and "t" before the "th," reflecting its derivation from "eight."
Easily confused with eighth
"Height" means how tall something is, while "eighth" is the ordinal form of eight; they share a similar spelling pattern but entirely different meanings.