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• rhesus
  rhesus

  noun

  a macaque, Macaca mulatta, of India, used in experimental medicine.
• Rhesus
  Rhesus

  noun

  Greek myth a king of Thrace, who arrived in the tenth year of the Trojan War to aid Troy. Odysseus and Diomedes stole his horses because an oracle had said that if these horses drank from the River Xanthus, Troy would not fall

rhesus

American  

[ree-suhs] / ˈri səs /

noun

1. a macaque, Macaca mulatta, of India, used in experimental medicine.

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Rhesus British  

/ ˈriːsəs /

noun

1. Greek myth a king of Thrace, who arrived in the tenth year of the Trojan War to aid Troy. Odysseus and Diomedes stole his horses because an oracle had said that if these horses drank from the River Xanthus, Troy would not fall

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Other Word Forms

• rhesian
  adjective

Etymology

Origin of rhesus

1830–40; < New Latin, arbitrary use of Latin Rhēsus name of a Thracian king allied with Troy < Greek Rhêsos

Example Sentences

See Examples For:

rhesus Rhesus

In the study, pregnant rhesus monkeys were placed into different conditions.

From Science Daily ● Feb. 6, 2026

On a tiny island called Cayo Santiago off the coast of Puerto Rico exists a colony of about 1,800 rhesus macaques.

From Salon ● Mar. 16, 2025

The first macaque monkeys were cloned in 2018, but rhesus monkeys are preferred for medical researchers, because of their genetic similarity to humans.

From BBC ● Jan. 16, 2024

And it has proved harder still with rhesus monkeys, with no births until the research team succeeded two years ago.

From BBC ● Jan. 16, 2024

Neel strained to hear the sound of a soft mew of a cub, but the chatter of the rhesus monkeys and Headmaster’s loud panting made it impossible to hear anything else.

From "Tiger Boy" by Mitali Perkins

Macaque species score even lower, ranging from 2.3% in Japanese macaques to just 1% in Rhesus macaques.

From Science Daily ● Jan. 22, 2026

Zika, a mosquito-borne virus first identified in 1947 in a Rhesus macaque monkey, continues to perplex scientists in many ways nearly 80 years later.

From Salon ● Feb. 3, 2025

Rhesus monkeys are found in the wild in Asia, with populations in Afghanistan through India, Thailand, Vietnam and China.

From BBC ● Jan. 16, 2024

The Rh blood group was first discovered in Rhesus monkeys.

From Textbooks ● Jun. 9, 2022

But the scepticism first declared by Valcknaer has gained ground, and the Rhesus is now almost universally recognized as spurious.

From Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 8 "Ethiopia" to "Evangelical Association" by Various