/ Dictionary / Index J Jy: Meaning and Definition of Find definitions for: Jy Pronunciation: [key] jansky; janskies. Jy. Pronunciation: [key] July. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. J.W.V. Jylland Related Content Daily Word Quiz: modify Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language