/ Dictionary / Index P phase velocity: Meaning and Definition of Find definitions for: phase' veloc"ity Pronunciation: [key] — Physics. Physics. the velocity with which a simple harmonic wave is propagated, equal to the wavelength divided by the period of vibration. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. phase space -phasia Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language