1Attributive and in the genitive. Used with reference to methods for the selective culture and identification of enteric bacteria; specifically (now chiefly in "MacConkey agar") designating a bacterial culture medium containing bile salts, lactose and a pH indicator.
2A MacConkey culture medium; especially. MacConkey agar.
Early 20th century. From the name of Alfred Theodore MacConkey, British bacteriologist, who developed the methods.