autoisolysin [ô′tō-ī-sŏl′ĭ-sĭn, -ī′sō-lī′-] n. An antibody that with complement causes lysis of cells in the organism in whose body the lysin is formed, as well as in others of the same species. Liberaldictionary.com What It Really Means to Call Someone "Crude" Can You Translate These Famous Phrases From Emoji? These Are the Longest Words in English These Are the Saddest Phrases in English The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.