# eighteenth

/ˈeɪˈtinθ/ (US) · /ˈeɪtiːnθ/ (UK)

Source: https://englishreference.com/word/eighteenth
Updated: 2026-08-08

## Senses

### 1. position in a sequence

numeral · CEFR A2

coming after the seventeenth and before the nineteenth.

For teachers: the ordinal number matching the cardinal number eighteen in a sequence.

- My office is on the eighteenth floor of the building.
- The eighteenth century was a period of significant intellectual and political upheaval across the European continent.

### 2. a fraction

noun · CEFR B2

one of eighteen equal parts of a whole.

For teachers: one of eighteen equal parts into which a whole is divided.

- An eighteenth of the budget was spent on office supplies.
- The mathematician calculated that each segment represented exactly one eighteenth of the total surface area.

### 3. a birthday party

noun · CEFR B1 · Informal · British English

a party to celebrate someone's eighteenth birthday.

For teachers: a social gathering or celebration held in honour of an individual's eighteenth birthday.

- Are you going to Sarah's eighteenth on Saturday night?
- The venue was fully booked for a local student's eighteenth, resulting in significant noise complaints from the neighbours.

Usage: Usually used with a possessive, such as 'my eighteenth' or 'his eighteenth'.

## Examples

- Today is my eighteenth birthday.
- She finished in eighteenth place out of fifty runners in the marathon.
- The eighteenth century was a period of significant intellectual and social change across Europe, often referred to as the Age of Enlightenment.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.