/ Dictionary / Index P pencil beam: Meaning and Definition of Find definitions for: pen'cil beam" Pronunciation: [key] a cone-shaped radar beam. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pencil pencil box Related Content Daily Word Quiz: resilient Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language