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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

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 rhesus macaque fugitives busted out of Alpha Genesis, a company that breeds primates for medical testing and research, and are on the loose in a part of the state known as the Lowcountry.

From BBC • Nov. 7, 2024

By decoding monkeys' reward expectations from the neural activity, they were able to predict how long the rhesus monkeys were willing to wait for a higher reward and when they decided to choose another option.

From Science Daily • Mar. 6, 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