IgG

Immunology.
  1. immunoglobulin G: a class of circulating antibodies predominant in serum, produced by plasma cells and memory cells in response to pathogens and other foreign substances, able to pass through the placental wall to the fetal circulation to impart immune defense for the period of infancy.

Origin of IgG

First recorded in 1960–65
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018