/ Dictionary / Index J jansky: Meaning and Definition of Find definitions for: jan•sky Pronunciation: ( jan'skē), [key] — pl. -skies. a unit of flux density for electromagnetic radiation, used chiefly in radio astronomy. Abbr.: Jy Jan•sky Pronunciation: ( jan'skē), [key] — n. 1905–50, U.S. engineer: pioneer in radio astronomy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Jansenism Januarius Related Content Daily Word Quiz: portent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language