/ Dictionary / Index P point source: Meaning and Definition of Find definitions for: point' source" Pronunciation: [key] — Physics, Optics. Physics,Optics. a source of radiation sufficiently distant compared to its length and width that it can be considered as a point. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pointsman point spread Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language