| Noun | 1. | 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 anemiaantigen - any substance (as a toxin or enzyme) that stimulates the production of antibodies | |
| 2. | Rh - a white hard metallic element that is one of the platinum group and is found in platinum ores; used in alloys with platinummetal, metallic element - any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc. | |
| 3. | 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 releasing hormone causes the anterior pituitary to secrete a specific hormone | |