# REX

/ˈɹɛks/ (US)

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

## Senses

### 1. the reigning king

noun · CEFR C2 · Formal

the title for a king, used in legal cases or on coins.

For teachers: the reigning king, used especially in the titles of legal cases or on currency to indicate the state.

- The court case was listed as Rex v. Smith during the king's reign.
- In British legal history, the designation of the prosecutor changes from Rex to Regina depending on the gender of the current sovereign.

Usage: Always capitalized when referring to a specific monarch in a legal title.

### 2. ancient Roman king

noun · CEFR C2 · Formal

the title for a king in ancient Rome.

For teachers: the title held by the seven legendary kings of Rome before the establishment of the Republic.

- Tarquin the Proud was the last Rex of Rome before it became a republic.
- Historians debate the exact powers held by the early Rex, as the transition to the consulship suggests a significant shift in executive authority.

### 3. animal breed/fur type

noun · CEFR C1 · Technical

a type of rabbit or cat with very short, soft, and curly fur.

For teachers: an animal, particularly a rabbit or cat, possessing a genetic recessive mutation that results in a plush coat lacking guard hairs.

- The Rex rabbit is famous for its fur, which feels like velvet.
- The breeder specialized in Cornish Rex cats, a variety known for their distinctive wavy coats and large ears.

### 4. to breed for fur

verb · CEFR C2 · Technical

to breed an animal so that it has short, soft fur.

For teachers: to selectively breed an animal to express the recessive rex gene for coat texture.

- The farm began to rex their rabbits to meet the demand for soft pelts.
- Efforts to rex the feline population resulted in several distinct breeds recognized by international registries.

Usage: This verb is transitive and usually appears in technical breeding contexts.

## Examples

- The court case was listed as Rex v. Smith.
- In many Commonwealth countries, legal proceedings are brought in the name of Rex when a king is on the throne.
- The transition from Regina to Rex in legal documentation reflects the change in the gender of the monarch, though the underlying authority of the Crown remains constant.

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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.