reagin
re·agin
noun \rē-ˈā-jən, -gən\Definition of REAGIN
1
: a substance that is in the blood of individuals with syphilis and is responsible for positive serological reactions for syphilis
2
: an antibody (as IgE in humans) that mediates hypersensitive allergic reactions of rapid onset
—re·agin·ic \ˌrē-ə-ˈjin-ik, -ˈgin-\ adjective








