/ Dictionary / Index Y Yerkes Observatory: Meaning and Definition of Find definitions for: Yer'kes Observ'atory Pronunciation: [key] an astronomical observatory located in Williams Bay, Wisconsin, affiliated with the University of Chicago, and having a 40-in. (102-cm) refracting telescope, the largest refractor in the world. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Yerkes Yerkish Related Content Daily Word Quiz: coincidence Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language