Rh factor

noun \ ˌär-ˈāch- \

Definition of Rh factor

: any of one or more genetically determined antigens present in the red blood cells of most persons and of higher animals and capable of inducing intense immunogenic reactions

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Origin and Etymology of rh factor

rhesus monkey (in which it was first detected)

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First Known Use: 1942

in the meaning defined above

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RH FACTOR Defined for English Language Learners

Rh factor

noun

Definition of Rh factor for English Language Learners

medical : a substance that is present in the red blood cells of most people

Medical Dictionary

Rh factor

noun \ ˈär-ˈāch- \

medical Definition of Rh factor

: a genetically determined protein on the red blood cells of some people that is one of the substances used to classify human blood as to compatibility for transfusion and that when present in a fetus but not in the mother causes a serious immunogenic reaction in which the mother produces antibodies that cross the placenta and attack the red blood cells of the fetus — called also rhesus factor