# Rhesus factor

> English word · Noun

## Definitions
1. An antigen of the Rhesus system; understood unless otherwise specified to refer to Rhesus factor D (RhD), which appears on the surface of the red blood cells of most (85%) humans. An incompatibility between the Rh-blood types of a mother and her baby may cause serious disease for the baby.

## Etymology
The antigen was discovered in connection with a research of rhesus monkeys.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/rhesus-factor