/ Dictionary / Index J Johnston's organ: Meaning and Definition of Find definitions for: John'ston's or'gan Pronunciation: ( jon'stunz), [key] — Entomol. Entomol. a sense organ in the second segment of the antenna of an insect, sensitive to movements of the antenna's flagellum, as when the insect is in flight. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Johnston Johnstown Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language