/ Dictionary / Index P Ptolemaeus: Meaning and Definition of Find definitions for: Ptol•e•mae•us Pronunciation: (tol"u-mā'us), [key] — n. a walled plain in the third quadrant of the face of the moon: about 90 miles (144 km) in diameter. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. PTO Ptolemaic Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language