# rarest

/ˈɹɛɹəst/ (US) · /ɹˈeəɹəst/ (UK) · CEFR A2 · Adjective

Source: https://englishreference.com/word/rarest
Updated: 2026-05-09

## Definition

describes something that is the most difficult to find because very few of them exist. It is the superlative form of 'rare'.

For teachers: the superlative form of 'rare'; describes the least common or most infrequent item within a set. Often used to describe physical objects, biological species, or occurrences with the lowest statistical probability.

## Examples

- This is the rarest diamond in the world.
- Collectors spent decades searching for the rarest stamp in the series to complete their set.
- The conservation team focused their efforts on the rarest subspecies of orchid, which was found in only one remote valley in the Andes.

## Pitfalls

- Not "the most rarest" but "the rarest" — Since 'rare' is a one-syllable adjective, it takes the '-est' ending; using 'most' as well is a double superlative error.

## Usage notes

- Superlative form; typically preceded by the definite article 'the'.

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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.