| Main Entry: | allergen |
| Part of Speech: | noun |
| Definition: | irritant |
Synonyms: |
antigen, dander, dust mite, foreign substance, immune trigger, irritant, pollen, ragweed |
| Main Entry: | Rh factor |
| Part of Speech: | noun |
| Definition: | blood group antigen |
Synonyms: |
Rh antigen, Rh-negative, Rh-positive, Rh-type, Rhesus factor, antigen, blood group |
| Main Entry: | serum |
| Part of Speech: | noun |
| Definition: | antitoxin |
Synonyms: |
agglutinin, agglutinogen, agglutinoid, antibody, antigen, antiserum, immunizer, immunotoxin, vaccine |