/ Dictionary / Index J johnin: Meaning and Definition of Find definitions for: joh•nin Pronunciation: (yō'nin), [key] — n. Vet. Med. a sterile solution prepared from the growth products of the bacillus Mycobacterium paratuberculosis, used chiefly in the diagnosis of Johne's disease. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. John Henry Johnna Related Content Daily Word Quiz: languid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language