/ Dictionary / Index G geometrical optics: Meaning and Definition of Find definitions for: geomet'rical op'tics Pronunciation: [key] the branch of optics dealing with light as rays, esp. in the study of the effects of lenses and mirrors on light beams and of their combination in optical instruments. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. geometric geometrical pace Related Content Daily Word Quiz: lyceum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language