/ Dictionary / Index P Pecos Bill: Meaning and Definition of Find definitions for: Pe'cos Bill' Pronunciation: [key] a legendary cowboy of the American frontier who performed such fabulous feats as digging the Rio Grande. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Pecos pecs Related Content Daily Word Quiz: posthumous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language