eightieth
B1Neutral (used across formal, academic, and informal contexts)
Definition
Meaning
The ordinal number corresponding to the cardinal number 80; position 80 in a sequence.
One of 80 equal parts of a whole.
Linguistics
Semantic Notes
Functions primarily as an ordinal number (adjective) or a fraction (noun).
Dialectal Variation
British vs American Usage
Differences
No significant differences in form or core meaning. Spelling is identical. Potential minor differences in the pronunciation of the final 'th'.
Connotations
Neutral; no special connotations.
Frequency
Equally frequent in both varieties due to its numeric nature.
Vocabulary
Collocations
Grammar
Valency Patterns
ordinal + noun (the eightieth anniversary)noun + ordinal (chapter eightieth)fraction noun + of + noun (an eightieth of the total)Vocabulary
Synonyms
Strong
Neutral
Vocabulary
Antonyms
Usage
Context Usage
Business
Rare, except in contexts like 'eighty years of operation' or discussing fractional ownership.
Academic
Used in historical chronology, statistical percentiles, and fractional mathematics.
Everyday
Most commonly used for birthdays and anniversaries.
Technical
Used in precise sequencing, measurements, and fractional calculations.
Examples
By Part of Speech
adjective
British English
- The couple celebrated their eightieth wedding anniversary with a quiet party.
- She finished in eightieth position in the marathon.
American English
- The company is marking its eightieth year in business this fall.
- This is the president's eightieth press conference.
Examples
By CEFR Level
- My grandmother is eightieth years old.
- Turn to page eightieth.
- They celebrated their eightieth anniversary last week.
- He came in eightieth out of a hundred runners.
- The treaty was signed in the eightieth year of the century.
- Only an eightieth of the original sample remained usable for testing.
- The artist's eightieth exhibition showcased a radical departure from her earlier work.
- A mere eightieth of a percent variation can significantly impact the experimental results.
Learning
Memory Aids
Mnemonic
Think of 'eight-y' (80) with the common ordinal suffix '-ieth', like 'twentieth' or 'thirtieth'.
Conceptual Metaphor
POSITION AS A NUMBER (The eightieth in line is far back), PART-WHOLE (An eightieth is a tiny slice).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid confusing with 'восьмидесятый' which is correct for the ordinal. The fractional noun 'одна восьмидесятая' is the direct equivalent for 'an eightieth'.
Common Mistakes
- Misspelling as 'eighteith' or 'eithtieth'.
- Incorrect pronunciation of the '-tieth' ending.
- Using it as a cardinal number (e.g., 'I have eightieth books').
Practice
Quiz
In the fraction 1/80, how do you say the denominator?
FAQ
Frequently Asked Questions
It can be both. As an adjective: 'the eightieth day'. As a noun (fraction): 'one eightieth of the prize money'.
It is spelled E-I-G-H-T-I-E-T-H. The base is 'eight' with the ordinal suffix '-ieth'. There is no 'y' in the spelling.
A common mistake is misspelling it as 'eithtieth' or 'eighteith', incorrectly transposing the 'i' and 'e' or misplacing the 't'.
Yes, but it's less common than for birthdays/anniversaries. For dates, we usually say 'the eightieth of May' is incorrect as there is no 80th day. For years, 'in the eightieth year of the reign' is possible but formal.