Definition of Rh

Noun: Rh

A blood group antigen possessed by Rh-positive people; if an Rh-negative person receives a blood transfusion from an Rh-positive person it can result in hemolysis and anaemia
- rhesus factor, Rh factor
A white hard metallic element that is one of the platinum group and is found in platinum ores; used in alloys with platinum
- rhodium, atomic number 45

Noun: RH

Any of several hormones produced in the hypothalamus and carried by a vein to the anterior pituitary gland where they stimulate the release of anterior pituitary hormones; each of these hormones causes the anterior pituitary to secrete a specific hormone
- releasing hormone, releasing factor, hypothalamic releasing hormone, hypothalamic releasing factor